diff --git a/hgext/rebase.py b/hgext/rebase.py
--- a/hgext/rebase.py
+++ b/hgext/rebase.py
@@ -551,8 +551,16 @@
         if not self.keepf:
             if self.collapsef:
                 collapsedas = newnode
+
+        fm = None
+        if repo.ui.configbool('experimental', 'showhashchanges'):
+            fm = repo.ui.formatter('rebase', opts)
+
         clearrebased(ui, repo, self.destmap, self.state, self.skipped,
-                     collapsedas, self.keepf)
+                     collapsedas, self.keepf, fm=fm)
+
+        if fm:
+            fm.end()
 
         clearstatus(repo)
         clearcollapsemsg(repo)
@@ -1517,7 +1525,7 @@
     return originalwd, destmap, state
 
 def clearrebased(ui, repo, destmap, state, skipped, collapsedas=None,
-                 keepf=False):
+                 keepf=False, fm=None):
     """dispose of rebased revision at the end of the rebase
 
     If `collapsedas` is not None, the rebase was a collapse whose result if the
@@ -1541,6 +1549,9 @@
                     succs = (newnode,)
                 replacements[oldnode] = succs
     scmutil.cleanupnodes(repo, replacements, 'rebase', moves)
+    if fm:
+        fm.startitem()
+        scmutil.showchanges(replacements, fm)
 
 def pullrebase(orig, ui, repo, *args, **opts):
     'Call rebase after pull if the latter has been invoked with --rebase'
diff --git a/mercurial/configitems.py b/mercurial/configitems.py
--- a/mercurial/configitems.py
+++ b/mercurial/configitems.py
@@ -236,6 +236,9 @@
 coreconfigitem('experimental', 'revlogv2',
     default=None,
 )
+coreconfigitem('experimental', 'showhashchanges',
+    default=False,
+)
 coreconfigitem('experimental', 'spacemovesdown',
     default=False,
 )
diff --git a/tests/test-rebase-base.t b/tests/test-rebase-base.t
--- a/tests/test-rebase-base.t
+++ b/tests/test-rebase-base.t
@@ -415,4 +415,51 @@
   |
   o  0: A
   
+Enabling obsolete markers
+
+  $ cat >> $HGRCPATH << EOF
+  > [experimental]
+  > stabilization=createmarkers
+  > showhashchanges=True
+  > EOF
+
+Testing the experimental.showhashchanges config
+
+  $ hg rebase -s 4 -d 2
+  rebasing 4:abc67d0cf023 "C"
+  rebasing 5:a701fddfacec "D" (tip)
+  'abc67d0cf023' --> ['2e4b11ea9404']
+  'a701fddfacec' --> ['003ba25ccc56']
+  'abc67d0cf023' --> ['2e4b11ea9404']
+
+  $ hg tglog
+  o  7: D
+  |
+  o  6: C
+  |
+  | o  3: B
+  |/
+  o  2: Z
+  |
+  o  1: Y
+  |
+  o  0: A
+  
+
+JSON output using the config
+
+  $ hg rebase -s 6 -d 3 -Tjson
+  rebasing 6:2e4b11ea9404 "C"
+  rebasing 7:003ba25ccc56 "D" (tip)
+  [
+   {
+    "hashchanges": {"003ba25ccc56": ["38bd5f90ba6a"], "2e4b11ea9404": ["583565ab89ac"]}
+   }
+  ]
+
+Using `-q` to make sure ui.status() things don't appear
+
+  $ hg rebase -s 8 -d 2 -T '{hashchanges|json}' -q
+  {"38bd5f90ba6a": ["28cb79571ec7"], "583565ab89ac": ["89a178738706"]} (no-eol)
+
   $ cd ..