diff --git a/icu4c/source/common/unicode/platform.h.in b/icu4c/source/common/unicode/platform.h.in
index 7bd98259a38..c8604d6e9ee 100644
--- a/icu4c/source/common/unicode/platform.h.in
+++ b/icu4c/source/common/unicode/platform.h.in
@@ -77,19 +77,6 @@
 #define U_HAVE_UINT64_T @HAVE_UINT64_T@
 #endif
 
-
-/*===========================================================================*/
-/* Platform/Language determination                                           */
-/*===========================================================================*/
-
-#ifdef macintosh
-#ifdef XP_MAC
-#undef XP_MAC
-#endif
-#define XP_MAC 1
-#include <string.h>
-#endif
-
 /*===========================================================================*/
 /* Generic data types                                                        */
 /*===========================================================================*/
diff --git a/icu4c/source/common/unicode/pmacos.h b/icu4c/source/common/unicode/pmacos.h
deleted file mode 100644
index 36a7ade09d0..00000000000
--- a/icu4c/source/common/unicode/pmacos.h
+++ /dev/null
@@ -1,140 +0,0 @@
-/*
-******************************************************************************
-*
-*   Copyright (C) 1997-2001, International Business Machines
-*   Corporation and others.  All Rights Reserved.
-*
-******************************************************************************
-*
-*  FILE NAME : pmacos.h
-*
-*   Date        Name        Description
-*   05/13/98    nos         Creation (content moved here from ptypes.h).
-*   03/02/99    stephen     Added AS400 support.
-*   03/30/99    stephen     Added Linux support.
-*   04/13/99    stephen     Reworked for autoconf.
-*   08/26/00    srl         Moved to pmacos.h
-******************************************************************************
-*/
-
-/* Define the platform we're on. */
-#ifndef macintosh
-#define macintosh
-#endif
-
-#ifndef XP_MAC
-#define  XP_MAC
-#endif
-
-/* We want the console window (argc/argv) */
-/*
-#ifndef XP_MAC_CONSOLE
-#define  XP_MAC_CONSOLE
-#endif
-*/
-
-/* Define whether inttypes.h is available */
-#define U_HAVE_INTTYPES_H 0
-
-/* Define whether namespace is supported */
-#define U_HAVE_NAMESPACE 1
-
-/*
- * Define what support for C++ streams is available.
- *     If U_IOSTREAM_SOURCE is set to 199711, then <iostream> is available
- * (1997711 is the date the ISO/IEC C++ FDIS was published), and then
- * one should qualify streams using the std namespace in ICU header
- * files.
- *     If U_IOSTREAM_SOURCE is set to 198506, then <iostream.h> is
- * available instead (198506 is the date when Stroustrup published
- * "An Extensible I/O Facility for C++" at the summer USENIX conference).
- *     If U_IOSTREAM_SOURCE is 0, then C++ streams are not available and
- * support for them will be silently suppressed in ICU.
- *
- */
-
-#ifndef U_IOSTREAM_SOURCE
-#define U_IOSTREAM_SOURCE 198506    /* Wish we could use 199711 but that breaks while compiling chariter.cpp */
-#endif
-
-/* Determines whether specific types are available */
-#define HAVE_INT8_T 0
-#define HAVE_UINT8_T 0
-#define HAVE_INT16_T 0
-#define HAVE_UINT16_T 0
-#define HAVE_INT32_T 0
-#define HAVE_UINT32_T 0
-#define HAVE_BOOL_T 0
-
-/* Determines the endianness of the platform */
-#define U_IS_BIG_ENDIAN 1
-
-/*===========================================================================*/
-/* Generic data types                                                        */
-/*===========================================================================*/
-
-/* If your platform does not have the <inttypes.h> header, you may
-   need to edit the typedefs below. */
-#if U_HAVE_INTTYPES_H
-#include <inttypes.h>
-#else
-
-#if ! HAVE_INT8_T
-typedef signed char int8_t;
-#endif
-
-#if ! HAVE_UINT8_T
-typedef unsigned char uint8_t;
-#endif
-
-#if ! HAVE_INT16_T
-typedef signed short int16_t;
-#endif
-
-#if ! HAVE_UINT16_T
-typedef unsigned short uint16_t;
-#endif
-
-#if ! HAVE_INT32_T
-#   if defined(_LP64)
-      typedef signed int  int32_t;
-#   else
-      typedef signed long int32_t;
-#   endif
-#endif
-
-#if ! HAVE_UINT32_T
-#   if defined(_LP64)
-      typedef unsigned int  uint32_t;
-#   else
-      typedef unsigned long uint32_t;
-#   endif
-#endif
-
-#endif
-
-/*===========================================================================*/
-/* Character data types                                                      */
-/*===========================================================================*/
-
-#define U_HAVE_WCHAR_H      0
-#define U_SIZEOF_WCHAR_T    2
-
-#define U_HAVE_WCSCPY       0
-
-/*===========================================================================*/
-/* Symbol import-export control                                              */
-/*===========================================================================*/
-
-/* should be pragmas? */
-
-#define U_EXPORT /*__declspec(dllexport)*/
-#define U_EXPORT2
-#define U_IMPORT /*__declspec(dllimport)*/
-
-/*===========================================================================*/
-/* Programs used by ICU code                                                 */
-/*===========================================================================*/
-
-#define U_MAKE  "Make"
-
diff --git a/icu4c/source/common/unicode/umachine.h b/icu4c/source/common/unicode/umachine.h
index 3a55b42f9fb..d841f53480f 100644
--- a/icu4c/source/common/unicode/umachine.h
+++ b/icu4c/source/common/unicode/umachine.h
@@ -43,8 +43,6 @@
 
 #if defined(WIN32) || defined(_WIN32) || defined(WIN64) || defined(_WIN64)
 #   include "unicode/pwin32.h"
-#elif defined(__MWERKS__)
-#   include "unicode/pmacos.h"
 #else
 #   include "unicode/platform.h"
 #endif
diff --git a/icu4c/source/test/hdrtst/pfiles.txt b/icu4c/source/test/hdrtst/pfiles.txt
index 5415909d03c..95502b7f8b5 100644
--- a/icu4c/source/test/hdrtst/pfiles.txt
+++ b/icu4c/source/test/hdrtst/pfiles.txt
@@ -1,5 +1,3 @@
 # Copyright (c) 2001-2004 International Business Machines 
 # Corporation and others. All Rights Reserved.
-pmacos.h
-pos400.h
 pwin32.h