diff --git a/doc/hg.1.txt b/doc/hg.1.txt
--- a/doc/hg.1.txt
+++ b/doc/hg.1.txt
@@ -330,6 +330,7 @@ serve [options]::
     -p, --port <n>           port to use (default: 8000)
     -n, --name <name>        name to show in web pages (default: working dir)
     -t, --templatedir <path> web templates to use
+    -6, --ipv6               use IPv6 in addition to IPv4
 
 status [options] [files]::
     Show changed files in the working directory.  If no names are
diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -1002,7 +1002,7 @@ def serve(ui, repo, **opts):
             return default
 
     httpd = hgweb.create_server(repo.root, opts["name"], opts["templates"],
-                                opts["address"], opts["port"],
+                                opts["address"], opts["port"], opts["ipv6"],
                                 openlog('accesslog', sys.stdout),
                                 openlog('errorlog', sys.stderr))
     if ui.verbose:
@@ -1251,7 +1251,8 @@ table = {
           ('a', 'address', '', 'interface address'),
           ('n', 'name', os.getcwd(), 'repository name'),
           ('', 'stdio', None, 'for remote clients'),
-          ('t', 'templates', "", 'template map')],
+          ('t', 'templates', "", 'template map'),
+          ('6', 'ipv6', None, 'use IPv6 in addition to IPv4')],
          "hg serve [OPTION]..."),
     "^status": (status,
                 [('I', 'include', [], 'include path in search'),
diff --git a/mercurial/hgweb.py b/mercurial/hgweb.py
--- a/mercurial/hgweb.py
+++ b/mercurial/hgweb.py
@@ -6,7 +6,7 @@
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
-import os, cgi, time, re, difflib, sys, zlib
+import os, cgi, time, re, difflib, socket, sys, zlib
 from mercurial.hg import *
 from mercurial.ui import *
 
@@ -699,11 +699,14 @@ class hgweb:
         else:
             write(self.t("error"))
 
-def create_server(path, name, templates, address, port,
+def create_server(path, name, templates, address, port, use_ipv6 = False,
                   accesslog = sys.stdout, errorlog = sys.stderr):
 
     import BaseHTTPServer
 
+    class IPv6HTTPServer(BaseHTTPServer.HTTPServer):
+        address_family = socket.AF_INET6
+
     class hgwebhandler(BaseHTTPServer.BaseHTTPRequestHandler):
         def log_error(self, format, *args):
             errorlog.write("%s - - [%s] %s\n" % (self.address_string(),
@@ -774,10 +777,13 @@ def create_server(path, name, templates,
                 sys.argv, sys.stdin, sys.stdout, sys.stderr = save
 
     hg = hgweb(path, name, templates)
-    return BaseHTTPServer.HTTPServer((address, port), hgwebhandler)
+    if use_ipv6:
+        return IPv6HTTPServer((address, port), hgwebhandler)
+    else:
+        return BaseHTTPServer.HTTPServer((address, port), hgwebhandler)
 
-def server(path, name, templates, address, port,
+def server(path, name, templates, address, port, use_ipv6 = False,
            accesslog = sys.stdout, errorlog = sys.stderr):
-    httpd = create_server(path, name, templates, address, port,
+    httpd = create_server(path, name, templates, address, port, use_ipv6,
                           accesslog, errorlog)
     httpd.serve_forever()