diff --git a/rhodecode/model/db.py b/rhodecode/model/db.py
--- a/rhodecode/model/db.py
+++ b/rhodecode/model/db.py
@@ -4002,6 +4002,14 @@ class _PullRequestBase(BaseModel):
     def reviewer_data_json(self):
         return json.dumps(self.reviewer_data)
 
+    @property
+    def work_in_progress(self):
+        """checks if pull request is work in progress by checking the title"""
+        title = self.title.upper()
+        if re.match(r'^(\[WIP\]\s*|WIP:\s*|WIP\s+)', title):
+            return True
+        return False
+
     @hybrid_property
     def description_safe(self):
         from rhodecode.lib import helpers as h
diff --git a/rhodecode/model/pull_request.py b/rhodecode/model/pull_request.py
--- a/rhodecode/model/pull_request.py
+++ b/rhodecode/model/pull_request.py
@@ -1614,6 +1614,7 @@ class MergeCheck(object):
     PERM_CHECK = 'perm'
     REVIEW_CHECK = 'review'
     MERGE_CHECK = 'merge'
+    WIP_CHECK = 'wip'
 
     def __init__(self):
         self.review_status = None
@@ -1638,6 +1639,15 @@ class MergeCheck(object):
         _ = translator
         merge_check = cls()
 
+        # title has WIP:
+        if pull_request.work_in_progress:
+            log.debug("MergeCheck: cannot merge, title has wip: marker.")
+
+            msg = _('WIP marker in title prevents from accidental merge.')
+            merge_check.push_error('error', msg, cls.WIP_CHECK, pull_request.title)
+            if fail_early:
+                return merge_check
+
         # permissions to merge
         user_allowed_to_merge = PullRequestModel().check_user_merge(
             pull_request, auth_user)
diff --git a/rhodecode/tests/models/test_pullrequest.py b/rhodecode/tests/models/test_pullrequest.py
--- a/rhodecode/tests/models/test_pullrequest.py
+++ b/rhodecode/tests/models/test_pullrequest.py
@@ -402,7 +402,7 @@ class TestPullRequestModel(object):
         assert pull_request.merge_rev is None
 
     def test_get_commit_ids(self, pull_request):
-        # The PR has been not merget yet, so expect an exception
+        # The PR has been not merged yet, so expect an exception
         with pytest.raises(ValueError):
             PullRequestModel()._get_commit_ids(pull_request)
 
@@ -433,6 +433,20 @@ class TestPullRequestModel(object):
         )
         assert type(title) == unicode
 
+    @pytest.mark.parametrize('title, has_wip', [
+        ('hello', False),
+        ('hello wip', False),
+        ('hello wip: xxx', False),
+        ('[wip] hello', True),
+        ('[wip] hello', True),
+        ('wip: hello', True),
+        ('wip hello', True),
+
+    ])
+    def test_wip_title_marker(self, pull_request, title, has_wip):
+        pull_request.title = title
+        assert pull_request.work_in_progress == has_wip
+
 
 @pytest.mark.usefixtures('config_stub')
 class TestIntegrationMerge(object):