diff --git a/hgext/mq.py b/hgext/mq.py
--- a/hgext/mq.py
+++ b/hgext/mq.py
@@ -395,6 +395,17 @@ def newcommit(repo, phase, *args, **kwar
 class AbortNoCleanup(error.Abort):
     pass
 
+def makepatchname(existing, title):
+    """Return a suitable filename for title, adding a suffix to make
+    it unique in the existing list"""
+    namebase = re.sub('[\s\W_]+', '_', title.lower()).strip('_')
+    name = namebase
+    i = 0
+    while name in existing:
+        i += 1
+        name = '%s__%s' % (namebase, i)
+    return name
+
 class queue(object):
     def __init__(self, ui, baseui, path, patchdir=None):
         self.basepath = path
@@ -2090,7 +2101,8 @@ class queue(object):
                     lastparent = p1
 
                     if not patchname:
-                        patchname = normname('%d.diff' % r)
+                        patchname = makepatchname(self.fullseries,
+                            repo[r].description().split('\n', 1)[0])
                     checkseries(patchname)
                     self.checkpatchname(patchname, force)
                     self.fullseries.insert(0, patchname)
diff --git a/tests/test-mq-qdelete.t b/tests/test-mq-qdelete.t
--- a/tests/test-mq-qdelete.t
+++ b/tests/test-mq-qdelete.t
@@ -155,11 +155,11 @@ qdel -k X && hg qimp -e X used to trigge
   $ hg init --mq
   $ hg qimport -r 3
   $ hg qpop
-  popping 3.diff
+  popping imported_patch_pc
   patch queue now empty
-  $ hg qdel -k 3.diff
-  $ hg qimp -e 3.diff
-  adding 3.diff to series file
+  $ hg qdel -k imported_patch_pc
+  $ hg qimp -e imported_patch_pc
+  adding imported_patch_pc to series file
   $ hg qfinish -a
   no patches applied
 
@@ -167,17 +167,17 @@ qdel -k X && hg qimp -e X used to trigge
 resilience to inconsistency: qfinish -a with applied patches not in series
 
   $ hg qser
-  3.diff
+  imported_patch_pc
   $ hg qapplied
   $ hg qpush
-  applying 3.diff
-  patch 3.diff is empty
-  now at: 3.diff
+  applying imported_patch_pc
+  patch imported_patch_pc is empty
+  now at: imported_patch_pc
   $ echo next >>  base
   $ hg qrefresh -d '1 0'
   $ echo > .hg/patches/series # remove 3.diff from series to confuse mq
   $ hg qfinish -a
-  revision 47dfa8501675 refers to unknown patches: 3.diff
+  revision 47dfa8501675 refers to unknown patches: imported_patch_pc
 
 more complex state 'both known and unknown patches
 
diff --git a/tests/test-mq-qimport.t b/tests/test-mq-qimport.t
--- a/tests/test-mq-qimport.t
+++ b/tests/test-mq-qimport.t
@@ -198,32 +198,32 @@ try to import --push
   now at: appendbar.diff
   $ hg qfin -a
   patch b.diff finalized without changeset message
-  $ touch .hg/patches/2.diff
+  $ touch .hg/patches/append_foo
   $ hg qimport -r 'p1(.)::'
-  abort: patch "2.diff" already exists
+  abort: patch "append_foo" already exists
   [255]
   $ hg qapplied
-  3.diff
+  append_bar
   $ hg qfin -a
-  $ rm .hg/patches/2.diff
+  $ rm .hg/patches/append_foo
   $ hg qimport -r 'p1(.)::' -P
   $ hg qpop -a
-  popping 3.diff
-  popping 2.diff
+  popping append_bar
+  popping append_foo
   patch queue now empty
-  $ hg qdel 3.diff
-  $ hg qdel -k 2.diff
+  $ hg qdel append_foo
+  $ hg qdel -k append_bar
 
 qimport -e
 
-  $ hg qimport -e 2.diff
-  adding 2.diff to series file
-  $ hg qdel -k 2.diff
+  $ hg qimport -e append_bar
+  adding append_bar to series file
+  $ hg qdel -k append_bar
 
 qimport -e --name newname oldexisitingpatch
 
-  $ hg qimport -e --name this-name-is-better 2.diff
-  renaming 2.diff to this-name-is-better
+  $ hg qimport -e --name this-name-is-better append_bar
+  renaming append_bar to this-name-is-better
   adding this-name-is-better to series file
   $ hg qser
   this-name-is-better
diff --git a/tests/test-mq-subrepo.t b/tests/test-mq-subrepo.t
--- a/tests/test-mq-subrepo.t
+++ b/tests/test-mq-subrepo.t
@@ -249,8 +249,8 @@ qpop
   reverting subrepo sub
   adding sub/a (glob)
   $ hg qpop
-  popping 1.diff
-  now at: 0.diff
+  popping 1
+  now at: 0
   $ hg status -AS
   C .hgsub
   C .hgsubstate
@@ -268,11 +268,11 @@ qpush
   reverting subrepo sub
   adding sub/a (glob)
   $ hg qpush
-  applying 1.diff
+  applying 1
    subrepository sub diverged (local revision: b2fdb12cd82b, remote revision: aa037b301eba)
   (M)erge, keep (l)ocal or keep (r)emote? m
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
-  now at: 1.diff
+  now at: 1
   $ hg status -AS
   C .hgsub
   C .hgsubstate
diff --git a/tests/test-rebase-mq-skip.t b/tests/test-rebase-mq-skip.t
--- a/tests/test-rebase-mq-skip.t
+++ b/tests/test-rebase-mq-skip.t
@@ -142,12 +142,12 @@ already has one local mq patch
   $ hg up -q qtip
 
   $ HGMERGE=internal:fail hg rebase
-  rebasing 1:b4bffa6e4776 "r1" (1.diff qbase)
+  rebasing 1:b4bffa6e4776 "r1" (qbase r1)
   note: rebase of 1:b4bffa6e4776 created no changes to commit
-  rebasing 2:c0fd129beb01 "r2" (2.diff)
-  rebasing 3:6ff5b8feed8e "r3" (3.diff)
+  rebasing 2:c0fd129beb01 "r2" (r2)
+  rebasing 3:6ff5b8feed8e "r3" (r3)
   note: rebase of 3:6ff5b8feed8e created no changes to commit
-  rebasing 4:094320fec554 "r4" (4.diff)
+  rebasing 4:094320fec554 "r4" (r4)
   unresolved conflicts (see hg resolve, then hg rebase --continue)
   [1]
 
@@ -155,20 +155,20 @@ already has one local mq patch
   (no more unresolved files)
 
   $ hg rebase --continue
-  already rebased 1:b4bffa6e4776 "r1" (1.diff qbase) as 057f55ff8f44
-  already rebased 2:c0fd129beb01 "r2" (2.diff) as 1660ab13ce9a
-  already rebased 3:6ff5b8feed8e "r3" (3.diff) as 1660ab13ce9a
-  rebasing 4:094320fec554 "r4" (4.diff)
+  already rebased 1:b4bffa6e4776 "r1" (qbase r1) as 057f55ff8f44
+  already rebased 2:c0fd129beb01 "r2" (r2) as 1660ab13ce9a
+  already rebased 3:6ff5b8feed8e "r3" (r3) as 1660ab13ce9a
+  rebasing 4:094320fec554 "r4" (r4)
   note: rebase of 4:094320fec554 created no changes to commit
-  rebasing 5:681a378595ba "r5" (5.diff)
-  rebasing 6:512a1f24768b "r6" (6.diff qtip)
+  rebasing 5:681a378595ba "r5" (r5)
+  rebasing 6:512a1f24768b "r6" (qtip r6)
   note: rebase of 6:512a1f24768b created no changes to commit
   saved backup bundle to $TESTTMP/b/.hg/strip-backup/b4bffa6e4776-b9bfb84d-backup.hg (glob)
 
   $ hg tglog
-  @  8: 'r5' tags: 5.diff qtip tip
+  @  8: 'r5' tags: qtip r5 tip
   |
-  o  7: 'r2' tags: 2.diff qbase
+  o  7: 'r2' tags: qbase r2
   |
   o  6: 'branch2-r6' tags: qparent
   |
diff --git a/tests/test-strip.t b/tests/test-strip.t
--- a/tests/test-strip.t
+++ b/tests/test-strip.t
@@ -431,9 +431,9 @@ strip of applied mq should cleanup statu
 applied patches before strip
 
   $ hg qapplied
-  2.diff
-  3.diff
-  4.diff
+  d
+  e
+  f
 
 stripping revision in queue
 
@@ -444,7 +444,7 @@ stripping revision in queue
 applied patches after stripping rev in queue
 
   $ hg qapplied
-  2.diff
+  d
 
 stripping ancestor of queue