diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -6154,6 +6154,7 @@
     [('C', 'clean', None, _('discard uncommitted changes (no backup)')),
     ('c', 'check', None, _('require clean working directory')),
     ('m', 'merge', None, _('merge uncommitted changes')),
+    ('', 'abort', False, _('abort interrupted update')),
     ('d', 'date', '', _('tipmost revision matching date'), _('DATE')),
     ('r', 'rev', '', _('revision'), _('REV'))
      ] + mergetoolopts,
@@ -6220,6 +6221,7 @@
     clean = opts.get(r'clean')
     check = opts.get(r'check')
     merge = opts.get(r'merge')
+    abort = opts.get(r'abort')
     if rev and node:
         raise error.Abort(_("please specify just one revision"))
 
@@ -6245,6 +6247,8 @@
         updatecheck = 'none'
 
     with repo.wlock():
+        if abort:
+            return hg.abortupdate(ui, repo)
         cmdutil.clearunfinished(repo)
         if date:
             rev = cmdutil.finddate(ui, repo, date)
diff --git a/mercurial/hg.py b/mercurial/hg.py
--- a/mercurial/hg.py
+++ b/mercurial/hg.py
@@ -984,6 +984,34 @@
     _showstats(repo, stats)
     return stats.unresolvedcount > 0
 
+def _unmarkandresolvelocal(ui, repo , ms):
+    """Helper for abortupdate(). This unmarks partially resolved files and then
+    resolves the update generated conflicts."""
+    wctx = repo[None]
+    for f in ms:
+        ms.mark(f, mergemod.MERGE_RECORD_UNRESOLVED_PATH)
+        ms.mark(f, mergemod.MERGE_RECORD_UNRESOLVED)
+        try:
+            overrides = {('ui', 'forcemerge'): ':local'}
+            with ui.configoverride(overrides, 'resolve'):
+                ms.preresolve(f, wctx)
+                ms.resolve(f, wctx)
+        finally:
+            ms.commit()
+
+def abortupdate(ui, repo):
+    """logic to abort an conflicted update"""
+    ms = mergemod.mergestate.read(repo)
+    node = ms.localctx.hex()
+    _unmarkandresolvelocal(ui, repo, ms)
+    repo.ui.status(_("aborting the update, updating back to"
+                     " %s\n") % node[:12])
+    mergemod.update(repo, node, branchmerge=False, force=False)
+    ms2 = mergemod.mergestate.read(repo)
+    _unmarkandresolvelocal(ui, repo, ms2)
+    ui.status(_("update aborted\n"))
+    ui.status(_("working directory is now at %s\n") % node[:12])
+
 def _incoming(displaychlist, subreporecurse, ui, repo, source,
         opts, buffered=False):
     """
diff --git a/tests/test-merge-tools.t b/tests/test-merge-tools.t
--- a/tests/test-merge-tools.t
+++ b/tests/test-merge-tools.t
@@ -4,6 +4,8 @@
   $ cat >> $HGRCPATH << EOF
   > [ui]
   > merge=
+  > [extensions]
+  > graphlog=
   > EOF
   $ hg init repo
   $ cd repo
@@ -2086,3 +2088,63 @@
   f = false
 
   $ cd ..
+
+Test for 'hg update --abort'
+
+  $ hg init test
+  $ cd test
+  $ echo before > file
+  $ hg add file
+  $ hg commit -mbefore
+  $ echo after > file
+  $ hg commit -mafter
+  $ echo edited > file
+
+Pre-update log and file content
+  $ hg glog
+  @  changeset:   1:47d1da7c1f80
+  |  tag:         tip
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     after
+  |
+  o  changeset:   0:dd67ebc4de84
+     user:        test
+     date:        Thu Jan 01 00:00:00 1970 +0000
+     summary:     before
+  
+
+  $ cat file
+  edited
+  $ hg update 0
+  merging file
+  warning: conflicts while merging file! (edit, then use 'hg resolve --mark')
+  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
+  use 'hg resolve' to retry unresolved file merges
+  [1]
+
+  $ hg update --abort
+  aborting the update, updating back to 47d1da7c1f80
+  merging file
+  warning: conflicts while merging file! (edit, then use 'hg resolve --mark')
+  update aborted
+  working directory is now at 47d1da7c1f80
+
+Post-update log and file content
+  $ hg glog
+  @  changeset:   1:47d1da7c1f80
+  |  tag:         tip
+  |  user:        test
+  |  date:        Thu Jan 01 00:00:00 1970 +0000
+  |  summary:     after
+  |
+  o  changeset:   0:dd67ebc4de84
+     user:        test
+     date:        Thu Jan 01 00:00:00 1970 +0000
+     summary:     before
+  
+
+  $ cat file
+  edited
+
+  $ cd ..