diff --git a/winsup/utils/Makefile.am b/winsup/utils/Makefile.am
index 6be5b12c2..75da1163b 100644
--- a/winsup/utils/Makefile.am
+++ b/winsup/utils/Makefile.am
@@ -31,6 +31,7 @@ bin_PROGRAMS = \
 	mkgroup \
 	mkpasswd \
 	mount \
+	newgrp \
 	passwd \
 	pldd \
 	profiler \
diff --git a/winsup/utils/newgrp.c b/winsup/utils/newgrp.c
new file mode 100644
index 000000000..012c3188f
--- /dev/null
+++ b/winsup/utils/newgrp.c
@@ -0,0 +1,101 @@
+/* newgrp.c
+
+This file is part of Cygwin.
+
+This software is a copyrighted work licensed under the terms of the
+Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
+details. */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <ctype.h>
+#include <string.h>
+#include <grp.h>
+#include <pwd.h>
+
+int
+main (int argc, const char **argv)
+{
+  struct group *gr;
+  gid_t gid;
+  const char *cmd;
+  const char **cmd_av;
+  const char *fake_av[2];
+
+  /* TODO: Implement '-' option */
+  /* TODO: Add command description to documentation */
+
+  if (argc < 2 || argv[1][0] == '-')
+    {
+      fprintf (stderr,
+	       "Usage: %1$s group [command [args...]]\n"
+	       "\n"
+	       "%1$s changes the current primary group for a command.\n"
+	       "The primary group must be member of the supplementary group\n"
+	       "list of the user.\n"
+	       "The command and its arguments are specified on the command\n"
+	       "line.  Default is the user's standard shell.\n",
+	       program_invocation_short_name);
+      return 1;
+    }
+  if (isdigit ((int) argv[1][0]))
+    {
+      char *e = NULL;
+
+      gid = strtol (argv[1], &e, 10);
+      if (e && *e != '\0')
+	{
+	  fprintf (stderr, "%s: invalid gid `%s'\n",
+		   program_invocation_short_name, argv[1]);
+	  return 2;
+	}
+      gr = getgrgid (gid);
+      if (!gr)
+	{
+	  fprintf (stderr, "%s: unknown group gid `%u'\n",
+		   program_invocation_short_name, gid);
+	  return 2;
+	}
+    }
+  else
+    {
+      gr = getgrnam (argv[1]);
+      if (!gr)
+	{
+	  fprintf (stderr, "%s: unknown group name `%s'\n",
+		   program_invocation_short_name, argv[1]);
+	  return 2;
+	}
+      gid = gr->gr_gid;
+    }
+  if (setgid (gid) != 0)
+    {
+      fprintf (stderr, "%s: can't switch primary group to `%s'\n",
+	       program_invocation_short_name, argv[1]);
+      return 2;
+    }
+  argc -= 2;
+  argv += 2;
+  if (argc < 1)
+    {
+      struct passwd *pw = getpwuid (getuid ());
+      if (!pw)
+	cmd = "/usr/bin/bash";
+      else
+	cmd = pw->pw_shell;
+      fake_av[0] = cmd;
+      fake_av[1] = NULL;
+      cmd_av = fake_av;
+    }
+  else
+    {
+      cmd = argv[0];
+      cmd_av = argv;
+    }
+  execvp (cmd, (char **) cmd_av);
+  fprintf (stderr, "%s: failed to start `%s': %s\n",
+	   program_invocation_short_name, cmd, strerror (errno));
+  return 3;
+}