diff --git a/icu4c/source/common/putil.cpp b/icu4c/source/common/putil.cpp
index 599dad9c97..5f09288613 100644
--- a/icu4c/source/common/putil.cpp
+++ b/icu4c/source/common/putil.cpp
@@ -882,7 +882,7 @@ static UBool compareBinaryFiles(const char* defaultTZFileName, const char* TZFil
             if (tzInfo->defaultTZBuffer == NULL) {
                 rewind(tzInfo->defaultTZFilePtr);
                 tzInfo->defaultTZBuffer = (char*)uprv_malloc(sizeof(char) * tzInfo->defaultTZFileSize);
-                fread(tzInfo->defaultTZBuffer, 1, tzInfo->defaultTZFileSize, tzInfo->defaultTZFilePtr);
+                sizeFileRead = fread(tzInfo->defaultTZBuffer, 1, tzInfo->defaultTZFileSize, tzInfo->defaultTZFilePtr);
             }
             rewind(file);
             while(sizeFileLeft > 0) {
diff --git a/icu4c/source/common/uloc_tag.c b/icu4c/source/common/uloc_tag.c
index c038026790..50bc40b04f 100644
--- a/icu4c/source/common/uloc_tag.c
+++ b/icu4c/source/common/uloc_tag.c
@@ -1320,7 +1320,7 @@ _appendLDMLExtensionAsKeywords(const char* ldmlext, ExtensionListEntry** appendT
         /* BCP47 representation of LDML key/type pairs */
         while (!isDone) {
             const char *pNextBcpKey = NULL;
-            int32_t nextBcpKeyLen;
+            int32_t nextBcpKeyLen = 0;
             UBool emitKeyword = FALSE;
 
             if (*pTag) {
diff --git a/icu4c/source/i18n/collationdatabuilder.cpp b/icu4c/source/i18n/collationdatabuilder.cpp
index 7a69133948..d111f631b3 100644
--- a/icu4c/source/i18n/collationdatabuilder.cpp
+++ b/icu4c/source/i18n/collationdatabuilder.cpp
@@ -1377,7 +1377,7 @@ CollationDataBuilder::buildContext(ConditionalCE32 *head, UErrorCode &errorCode)
             // Build the contractions trie.
             contractionBuilder.clear();
             // Entry for an empty suffix, to be stored before the trie.
-            uint32_t emptySuffixCE32;
+            uint32_t emptySuffixCE32 = 0;
             uint32_t flags = 0;
             if(firstCond->context.length() == suffixStart) {
                 // There is a mapping for the prefix and the single character c. (p|c)
diff --git a/icu4c/source/i18n/timezone.cpp b/icu4c/source/i18n/timezone.cpp
index cab1c67205..3cb8a7b79b 100644
--- a/icu4c/source/i18n/timezone.cpp
+++ b/icu4c/source/i18n/timezone.cpp
@@ -427,15 +427,15 @@ TimeZone::createTimeZone(const UnicodeString& ID)
      */
     TimeZone* result = createSystemTimeZone(ID);
 
-    if (result == 0) {
+    if (result == NULL) {
         U_DEBUG_TZ_MSG(("failed to load system time zone with id - falling to custom"));
         result = createCustomTimeZone(ID);
     }
-    if (result == 0) {
+    if (result == NULL) {
         U_DEBUG_TZ_MSG(("failed to load time zone with id - falling to Etc/Unknown(GMT)"));
         const TimeZone& unknown = getUnknown();
-        if (&unknown == NULL) { //  Illegal NULL reference!
-          U_DEBUG_TZ_MSG(("failed to getUnknown()"));
+        if (_UNKNOWN_ZONE == NULL) {                   // Cannot test (&unknown == NULL) because the
+          U_DEBUG_TZ_MSG(("failed to getUnknown()"));  // behavior of NULL references is undefined.
         } else {
           result = unknown.clone();
         }
diff --git a/icu4c/source/test/cintltst/capitst.c b/icu4c/source/test/cintltst/capitst.c
index 4a5bef3a3e..163bb6422d 100644
--- a/icu4c/source/test/cintltst/capitst.c
+++ b/icu4c/source/test/cintltst/capitst.c
@@ -2422,14 +2422,13 @@ static void TestGetKeywordValuesForLocale(void) {
 
     UErrorCode status = U_ZERO_ERROR;
     UEnumeration *keywordValues = NULL;
-    int32_t i, n, size, valueLength;
+    int32_t i, n, size;
     const char *locale = NULL, *value = NULL;
     UBool errorOccurred = FALSE;
 
     for (i = 0; i < UPRV_LENGTHOF(PREFERRED) && !errorOccurred; i++) {
         locale = PREFERRED[i][0];
         value = NULL;
-        valueLength = 0;
         size = 0;
 
         keywordValues = ucol_getKeywordValuesForLocale("collation", locale, TRUE, &status);
@@ -2438,6 +2437,7 @@ static void TestGetKeywordValuesForLocale(void) {
             break;
         }
         size = uenum_count(keywordValues, &status);
+        (void)size;
 
         for (n = 0; (value = PREFERRED[i][n+1]) != NULL; n++) {
             if (!uenum_contains(keywordValues, value, &status)) {
diff --git a/icu4c/source/test/cintltst/cbiditst.c b/icu4c/source/test/cintltst/cbiditst.c
index dd39b02744..6c7b4b288c 100644
--- a/icu4c/source/test/cintltst/cbiditst.c
+++ b/icu4c/source/test/cintltst/cbiditst.c
@@ -4376,7 +4376,7 @@ static const char* inverseBasic(UBiDi *pBiDi, const char *srcChars, int32_t srcL
     int32_t destLen;
     UChar src[MAXLEN], dest2[MAXLEN];
 
-    if (pBiDi == NULL || src == NULL) {
+    if (pBiDi == NULL || srcChars == NULL) {
         return NULL;
     }
     ubidi_setReorderingOptions(pBiDi, option);
diff --git a/icu4c/source/test/intltest/intltest.cpp b/icu4c/source/test/intltest/intltest.cpp
index 9998250f79..cfd944a184 100644
--- a/icu4c/source/test/intltest/intltest.cpp
+++ b/icu4c/source/test/intltest/intltest.cpp
@@ -445,7 +445,7 @@ void IntlTest::setICU_DATA() {
         }
         else {
             /* __FILE__ on MSVC7 does not contain the directory */
-            u_setDataDirectory(".."U_FILE_SEP_STRING".."U_FILE_SEP_STRING "data" U_FILE_SEP_STRING "out" U_FILE_SEP_STRING);
+            u_setDataDirectory(".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING "data" U_FILE_SEP_STRING "out" U_FILE_SEP_STRING);
             return;
         }
     }
@@ -1602,7 +1602,8 @@ const char *IntlTest::getSourceTestData(UErrorCode& /*err*/) {
     }
     else {
         /* We're in icu/source/test/intltest/Platform/(Debug|Release) */
-        srcDataDir = ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING "test" U_FILE_SEP_STRING "testdata"U_FILE_SEP_STRING;
+        srcDataDir = ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING
+                     "test" U_FILE_SEP_STRING "testdata" U_FILE_SEP_STRING;
     }
 #endif
     return srcDataDir;
@@ -1702,13 +1703,13 @@ const char *  IntlTest::pathToDataDirectory()
         }
         else {
             /* __FILE__ on MSVC7 does not contain the directory */
-            FILE *file = fopen(".." U_FILE_SEP_STRING ".."U_FILE_SEP_STRING "data" U_FILE_SEP_STRING "Makefile.in", "r");
+            FILE *file = fopen(".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING "data" U_FILE_SEP_STRING "Makefile.in", "r");
             if (file) {
                 fclose(file);
-                fgDataDir = ".." U_FILE_SEP_STRING ".."U_FILE_SEP_STRING "data" U_FILE_SEP_STRING;
+                fgDataDir = ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING "data" U_FILE_SEP_STRING;
             }
             else {
-                fgDataDir = ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING ".."U_FILE_SEP_STRING "data" U_FILE_SEP_STRING;
+                fgDataDir = ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING "data" U_FILE_SEP_STRING;
             }
         }
     }
diff --git a/icu4c/source/test/intltest/loctest.cpp b/icu4c/source/test/intltest/loctest.cpp
index 3053e30f43..2aad11a133 100644
--- a/icu4c/source/test/intltest/loctest.cpp
+++ b/icu4c/source/test/intltest/loctest.cpp
@@ -2136,6 +2136,7 @@ void LocaleTest::checkRegisteredCollators(const char *expectExtra) {
             foundExpected = TRUE;
             logln(UnicodeString("Found expected registered collator: ","") + expectStr);
         }
+        (void)foundExpected;    // Hush unused variable compiler warning.
 
         if( oldHash.geti(*locStr) == 0 ) {
             if(expectExtra != NULL && expectStr==*locStr) {
diff --git a/icu4c/source/test/iotest/filetst.c b/icu4c/source/test/iotest/filetst.c
index 6cd0ecc166..54838d1049 100644
--- a/icu4c/source/test/iotest/filetst.c
+++ b/icu4c/source/test/iotest/filetst.c
@@ -1,6 +1,6 @@
 /*
  **********************************************************************
- *   Copyright (C) 2004-2013, International Business Machines
+ *   Copyright (C) 2004-2014, International Business Machines
  *   Corporation and others.  All Rights Reserved.
  **********************************************************************
  *   file name:  filetst.c
@@ -239,7 +239,7 @@ static void TestFileFromICU(UFILE *myFile) {
     myString[2] = '!';
     myString[3] = '!';
     u_austrncpy(myString, myUString, sizeof(myUString)/sizeof(*myUString));
-    if (myString == NULL || strcmp(myString, "\t\n") != 0) {
+    if (strcmp(myString, "\t\n") != 0) {
         log_err("u_fgets got \"%s\"\n", myString);
     }
 
@@ -247,7 +247,7 @@ static void TestFileFromICU(UFILE *myFile) {
         log_err("u_fgets did not return myUString\n");
     }
     u_austrncpy(myString, myUString, sizeof(myUString)/sizeof(*myUString));
-    if (myString == NULL || strcmp(myString, "Pointer to integer (Count) %n: n=1  n=1\n") != 0) {
+    if (strcmp(myString, "Pointer to integer (Count) %n: n=1  n=1\n") != 0) {
         log_err("u_fgets got \"%s\"\n", myString);
     }
 
@@ -255,7 +255,7 @@ static void TestFileFromICU(UFILE *myFile) {
         log_err("u_fgets did not return myUString\n");
     }
     u_austrncpy(myString, myUString, sizeof(myUString)/sizeof(*myUString));
-    if (myString == NULL || strcmp(myString, "Pointer to integer Value: 37\n") != 0) {
+    if (strcmp(myString, "Pointer to integer Value: 37\n") != 0) {
         log_err("u_fgets got \"%s\"\n", myString);
     }
 
@@ -263,7 +263,7 @@ static void TestFileFromICU(UFILE *myFile) {
         log_err("u_fgets did not return myUString\n");
     }
     u_austrncpy(myString, myUString, sizeof(myUString)/sizeof(*myUString));
-    if (myString == NULL || strcmp(myString, "This is a long test123456789012345678901234567890123456789012345678901234567890\n") != 0) {
+    if (strcmp(myString, "This is a long test123456789012345678901234567890123456789012345678901234567890\n") != 0) {
         log_err("u_fgets got \"%s\"\n", myString);
     }
 
@@ -275,7 +275,7 @@ static void TestFileFromICU(UFILE *myFile) {
         log_err("u_fgets did not return myUString\n");
     }
     u_austrncpy(myString, myUString, sizeof(myUString)/sizeof(*myUString));
-    if (myString == NULL || strcmp(myString, "") != 0) {
+    if (strcmp(myString, "") != 0) {
         log_err("u_fgets got \"%s\"\n", myString);
     }
 
@@ -283,7 +283,7 @@ static void TestFileFromICU(UFILE *myFile) {
         log_err("u_fgets did not return myUString\n");
     }
     u_austrncpy(myString, myUString, sizeof(myUString)/sizeof(*myUString));
-    if (myString == NULL || strcmp(myString, "\t") != 0) {
+    if (strcmp(myString, "\t") != 0) {
         log_err("u_fgets got \"%s\"\n", myString);
     }
 
diff --git a/icu4c/source/test/letest/PortableFontInstance.cpp b/icu4c/source/test/letest/PortableFontInstance.cpp
index abbd8ee607..907ac4ab3a 100644
--- a/icu4c/source/test/letest/PortableFontInstance.cpp
+++ b/icu4c/source/test/letest/PortableFontInstance.cpp
@@ -1,7 +1,7 @@
 /*
  *******************************************************************************
  *
- *   Copyright (C) 1999-2013, International Business Machines
+ *   Copyright (C) 1999-2014, International Business Machines
  *   Corporation and others.  All Rights Reserved.
  *
  *******************************************************************************
@@ -97,7 +97,8 @@ PortableFontInstance::PortableFontInstance(const char *fileName, float pointSize
     // read in the directory
     SFNTDirectory tempDir;
 
-    fread(&tempDir, sizeof tempDir, 1, fFile);
+    size_t numRead = fread(&tempDir, sizeof tempDir, 1, fFile);
+    (void)numRead;
 
     le_int32 dirSize = sizeof tempDir + ((SWAPW(tempDir.numTables) - ANY_NUMBER) * sizeof(DirectoryEntry));
     const LETag headTag = LE_HEAD_TABLE_TAG;
@@ -116,7 +117,7 @@ PortableFontInstance::PortableFontInstance(const char *fileName, float pointSize
     }
 
     fseek(fFile, 0L, SEEK_SET);
-    fread((void *) fDirectory, sizeof(char), dirSize, fFile);
+    numRead = fread((void *) fDirectory, sizeof(char), dirSize, fFile);
 
     //
     // We calculate these numbers 'cause some fonts
@@ -242,7 +243,8 @@ const void *PortableFontInstance::readTable(LETag tag, le_uint32 *length) const
 
     if (table != NULL) {
         fseek(fFile, SWAPL(entry->offset), SEEK_SET);
-        fread(table, sizeof(char), *length, fFile);
+        size_t numRead = fread(table, sizeof(char), *length, fFile);
+        (void)numRead;
     }
 
     return table;
diff --git a/icu4c/source/test/letest/cmaps.cpp b/icu4c/source/test/letest/cmaps.cpp
index 7eedb000e3..0232546c72 100644
--- a/icu4c/source/test/letest/cmaps.cpp
+++ b/icu4c/source/test/letest/cmaps.cpp
@@ -1,6 +1,6 @@
 /***************************************************************************
 *
-*   Copyright (C) 1998-2013, International Business Machines
+*   Copyright (C) 1998-2014, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 ************************************************************************/
@@ -121,6 +121,9 @@ CMAPMapper *CMAPMapper::createUnicodeMapper(const CMAPTable *cmap)
     {
       subtable = (const CMAPEncodingSubtable *) ((const char *) cmap + foundOffset);
       //printf("%s:%d: using subtable #%d/%d type %d:%d\n", __FILE__, __LINE__, foundTable, nSubtables, foundPlatformID, foundPlatformSpecificID);
+      (void)foundPlatformID;   // Suppress unused variable compiler warnings.
+      (void)foundTable;
+      (void)foundPlatformSpecificID;
     } else {
       printf("%s:%d: could not find subtable.\n", __FILE__, __LINE__);
       return NULL;
diff --git a/icu4c/source/test/letest/letest.cpp b/icu4c/source/test/letest/letest.cpp
index f7f57437a0..d2715af1a2 100644
--- a/icu4c/source/test/letest/letest.cpp
+++ b/icu4c/source/test/letest/letest.cpp
@@ -415,15 +415,16 @@ const char *getSourceTestData() {
 #ifdef U_TOPSRCDIR
     srcDataDir = U_TOPSRCDIR U_FILE_SEP_STRING "test" U_FILE_SEP_STRING "testdata" U_FILE_SEP_STRING;
 #else
-    srcDataDir = ".."U_FILE_SEP_STRING".."U_FILE_SEP_STRING"test"U_FILE_SEP_STRING"testdata"U_FILE_SEP_STRING;
-    FILE *f = fopen(".."U_FILE_SEP_STRING".."U_FILE_SEP_STRING"test"U_FILE_SEP_STRING"testdata"U_FILE_SEP_STRING"rbbitst.txt", "r");
+    srcDataDir = ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING "test" U_FILE_SEP_STRING "testdata" U_FILE_SEP_STRING;
+    FILE *f = fopen(".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING "test" U_FILE_SEP_STRING "testdata" U_FILE_SEP_STRING "rbbitst.txt", "r");
 
     if (f != NULL) {
         /* We're in icu/source/test/letest/ */
         fclose(f);
     } else {
         /* We're in icu/source/test/letest/(Debug|Release) */
-        srcDataDir = ".."U_FILE_SEP_STRING".."U_FILE_SEP_STRING".."U_FILE_SEP_STRING"test"U_FILE_SEP_STRING"testdata"U_FILE_SEP_STRING;
+        srcDataDir =  ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING "test" 
+                      U_FILE_SEP_STRING "testdata" U_FILE_SEP_STRING;
     }
 #endif
 
@@ -1028,13 +1029,13 @@ static const char *ctest_dataOutDir()
         }
         else {
             /* __FILE__ on MSVC7 does not contain the directory */
-            FILE *file = fopen(".."U_FILE_SEP_STRING".."U_FILE_SEP_STRING "data" U_FILE_SEP_STRING "Makefile.in", "r");
+            FILE *file = fopen(".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING "data" U_FILE_SEP_STRING "Makefile.in", "r");
             if (file) {
                 fclose(file);
-                dataOutDir = ".."U_FILE_SEP_STRING".."U_FILE_SEP_STRING "data" U_FILE_SEP_STRING "out" U_FILE_SEP_STRING;
+                dataOutDir = ".." U_FILE_SEP_STRING ".." U_FILE_SEP_STRING "data" U_FILE_SEP_STRING "out" U_FILE_SEP_STRING;
             }
             else {
-                dataOutDir = ".."U_FILE_SEP_STRING".."U_FILE_SEP_STRING".."U_FILE_SEP_STRING "data" U_FILE_SEP_STRING "out" U_FILE_SEP_STRING;
+                dataOutDir = ".." U_FILE_SEP_STRING".." U_FILE_SEP_STRING".." U_FILE_SEP_STRING "data" U_FILE_SEP_STRING "out" U_FILE_SEP_STRING;
             }
         }
     }