diff --git a/runtime/bin/directory_win.cc b/runtime/bin/directory_win.cc
index ff5df13e2df..a9efc479d0e 100644
--- a/runtime/bin/directory_win.cc
+++ b/runtime/bin/directory_win.cc
@@ -5,21 +5,116 @@
 #include "bin/directory.h"
 
 bool Directory::Open(const char* path, intptr_t* dir) {
-  UNIMPLEMENTED();
-  return false;
+  return true;
 }
 
+
 bool Directory::Close(intptr_t dir) {
-  UNIMPLEMENTED();
-  return false;
+  return true;
 }
 
-void Directory::List(const char* path,
+
+static void HandleDir(char* dir_name,
+                      char* path,
+                      int path_length,
+                      Dart_Port dir_handler) {
+  if (dir_handler != 0 &&
+      strcmp(dir_name, ".") != 0 &&
+      strcmp(dir_name, "..") != 0) {
+    size_t written = snprintf(path + path_length,
+                              MAX_PATH - path_length,
+                              "%s",
+                              dir_name);
+    ASSERT(written == strlen(dir_name));
+    Dart_Handle name = Dart_NewString(path);
+    Dart_Post(dir_handler, name);
+  }
+}
+
+
+static void HandleFile(char* file_name,
+                       char* path,
+                       int path_length,
+                       Dart_Port file_handler) {
+  if (file_handler != 0) {
+    size_t written = snprintf(path + path_length,
+                              MAX_PATH - path_length,
+                              "%s",
+                              file_name);
+    ASSERT(written == strlen(file_name));
+    Dart_Handle name = Dart_NewString(path);
+    Dart_Post(file_handler, name);
+  }
+}
+
+
+static void HandleEntry(LPWIN32_FIND_DATA find_file_data,
+                        char* path,
+                        int path_length,
+                        Dart_Port file_handler,
+                        Dart_Port dir_handler) {
+  DWORD attributes = find_file_data->dwFileAttributes;
+  if ((attributes & FILE_ATTRIBUTE_DIRECTORY) != 0) {
+    HandleDir(find_file_data->cFileName, path, path_length, dir_handler);
+  } else {
+    HandleFile(find_file_data->cFileName, path, path_length, file_handler);
+  }
+}
+
+
+static void ComputeFullSearchPath(const char* dir_name,
+                                  char* path,
+                                  int* path_length) {
+  // GetFullPathName only works in a multi-threaded environment if
+  // SetCurrentDirectory is not used. We currently have no plan for
+  // exposing SetCurrentDirectory.
+  int written =
+    GetFullPathName(dir_name, MAX_PATH - *path_length, path, NULL);
+  *path_length += written;
+  written = snprintf(path + *path_length,
+                     MAX_PATH - *path_length,
+                     "%s",
+                     "\\*");
+  ASSERT(written == 2);
+  *path_length += written;
+}
+
+
+void Directory::List(const char* dir_name,
                      intptr_t dir,
                      bool recursive,
                      Dart_Port dir_handler,
                      Dart_Port file_handler,
                      Dart_Port done_handler,
                      Dart_Port dir_error_handler) {
-  UNIMPLEMENTED();
+  // TODO(ager): Handle recursive listing.
+  char path[MAX_PATH];
+  int path_length = 0;
+  ComputeFullSearchPath(dir_name, path, &path_length);
+
+  WIN32_FIND_DATA find_file_data;
+  HANDLE find_handle = FindFirstFile(path, &find_file_data);
+
+  // Adjust the path by removing the '*' used for the search.
+  path_length -= 1;
+  path[path_length] = '\0';
+
+  if (find_handle == INVALID_HANDLE_VALUE) {
+    Dart_Handle value = Dart_NewBoolean(false);
+    Dart_Post(done_handler, value);
+    return;
+  }
+
+  HandleEntry(&find_file_data, path, path_length, file_handler, dir_handler);
+  while (FindNextFile(find_handle, &find_file_data) != 0) {
+    HandleEntry(&find_file_data, path, path_length, file_handler, dir_handler);
+  }
+
+  bool result = GetLastError() == ERROR_NO_MORE_FILES;
+  BOOL closed = FindClose(find_handle);
+  if (!closed) {
+    result = false;
+  }
+  Dart_Handle value = Dart_NewBoolean(result);
+  Dart_Post(done_handler, value);
 }