diff --git a/command.py b/command.py
index 207ef46..38cacd3 100644
--- a/command.py
+++ b/command.py
@@ -126,7 +126,7 @@
         pass
     return project
 
-  def GetProjects(self, args, missing_ok=False, submodules_ok=False):
+  def GetProjects(self, args, groups='', missing_ok=False, submodules_ok=False):
     """A list of projects that match the arguments.
     """
     all_projects_list = self.manifest.projects
@@ -134,7 +134,8 @@
 
     mp = self.manifest.manifestProject
 
-    groups = mp.config.GetString('manifest.groups')
+    if not groups:
+        groups = mp.config.GetString('manifest.groups')
     if not groups:
       groups = 'default,platform-' + platform.system().lower()
     groups = [x for x in re.split(r'[,\s]+', groups) if x]
diff --git a/subcmds/forall.py b/subcmds/forall.py
index b93cd6d..96dc99d 100644
--- a/subcmds/forall.py
+++ b/subcmds/forall.py
@@ -120,6 +120,9 @@
     p.add_option('-r', '--regex',
                  dest='regex', action='store_true',
                  help="Execute the command only on projects matching regex or wildcard expression")
+    p.add_option('-g', '--groups',
+                 dest='groups',
+                 help="Execute the command only on projects matching the specified groups")
     p.add_option('-c', '--command',
                  help='Command (and arguments) to execute',
                  dest='command',
@@ -213,7 +216,7 @@
       self.manifest.Override(smart_sync_manifest_path)
 
     if not opt.regex:
-      projects = self.GetProjects(args)
+      projects = self.GetProjects(args, groups=opt.groups)
     else:
       projects = self.FindProjects(args)
 
diff --git a/subcmds/list.py b/subcmds/list.py
index 945c28d..ca51c5f 100644
--- a/subcmds/list.py
+++ b/subcmds/list.py
@@ -35,6 +35,9 @@
     p.add_option('-r', '--regex',
                  dest='regex', action='store_true',
                  help="Filter the project list based on regex or wildcard matching of strings")
+    p.add_option('-g', '--groups',
+                 dest='groups',
+                 help="Filter the project list based on the groups the project is in")
     p.add_option('-f', '--fullpath',
                  dest='fullpath', action='store_true',
                  help="Display the full work tree path instead of the relative path")
@@ -62,7 +65,7 @@
       sys.exit(1)
 
     if not opt.regex:
-      projects = self.GetProjects(args)
+      projects = self.GetProjects(args, groups=opt.groups)
     else:
       projects = self.FindProjects(args)