diff --git a/bugzilla2gitlab/config.py b/bugzilla2gitlab/config.py
index 44cdd32..000ebc1 100644
--- a/bugzilla2gitlab/config.py
+++ b/bugzilla2gitlab/config.py
@@ -32,6 +32,7 @@
         "include_bugzilla_link",
         "use_bugzilla_id",
         "verify",
+        "gitlab_skip_pre_migrated_issues",
     ],
 )
 
diff --git a/bugzilla2gitlab/migrator.py b/bugzilla2gitlab/migrator.py
index 497570a..a141bc4 100644
--- a/bugzilla2gitlab/migrator.py
+++ b/bugzilla2gitlab/migrator.py
@@ -18,8 +18,12 @@ def migrate(self, bug_list):
                 self.conf.bugzilla_user,
                 self.conf.bugzilla_password,
             )
+
+        bug_migrated = True # assume true for now
         for bug in bug_list:
-            self.migrate_one(bug)
+            bug_migrated = self.migrate_one(bug)
+
+        return bug_migrated
 
     def migrate_one(self, bugzilla_bug_id):
         """
@@ -28,4 +32,10 @@ def migrate_one(self, bugzilla_bug_id):
         print("Migrating bug {}".format(bugzilla_bug_id))
         fields = get_bugzilla_bug(self.conf.bugzilla_base_url, bugzilla_bug_id)
         issue_thread = IssueThread(self.conf, fields)
-        issue_thread.save()
+
+        if(self.conf.gitlab_skip_pre_migrated_issues and issue_thread.preexists):
+            print("Bug {} already migrated".format(bugzilla_bug_id))
+            return False
+        else:
+            issue_thread.save()
+            return True
diff --git a/bugzilla2gitlab/models.py b/bugzilla2gitlab/models.py
index bfa33aa..bb62df5 100644
--- a/bugzilla2gitlab/models.py
+++ b/bugzilla2gitlab/models.py
@@ -13,6 +13,7 @@ class IssueThread:
     def __init__(self, config, fields):
         global CONF
         CONF = config
+        self.preexists = False
         self.load_objects(fields)
 
     def load_objects(self, fields):
@@ -21,6 +22,14 @@ def load_objects(self, fields):
         If CONF.dry_run=False, then Attachments are created in GitLab in this step.
         """
         self.issue = Issue(fields)
+
+        """
+        If configured, check if the issue already exists
+        """
+        if(CONF.gitlab_skip_pre_migrated_issues is True and self.issue.find_issue()):
+            self.preexists = True
+            return
+
         self.comments = []
         """
         fields["long_desc"] gets peared down in Issue creation (above). This is because bugzilla
@@ -71,6 +80,30 @@ def __init__(self, bugzilla_fields):
         validate_user(bugzilla_fields["assigned_to"])
         self.load_fields(bugzilla_fields)
 
+    def find_issue(self):
+        url = "{}/issues?search{}&in=title".format(
+            CONF.gitlab_base_url, self.title,
+        )
+
+        data = {k: v for k, v in self.__dict__.items() if k in self.data_fields}
+
+        self.headers["sudo"] = self.sudo
+
+        response = _perform_request(
+            url,
+            "get",
+            headers=self.headers,
+            data=data,
+            json=True,
+            dry_run=CONF.dry_run,
+            verify=CONF.verify,
+        )
+
+        if(response and isinstance(response, list) and response[0] is not ""):
+            return True
+        else:
+            return False
+
     def load_fields(self, fields):
         self.title = fields["short_desc"]
         self.sudo = CONF.gitlab_users[CONF.bugzilla_users[fields["reporter"]]]
diff --git a/tests/test_bugzilla2gitlab.py b/tests/test_bugzilla2gitlab.py
index 3d1b7b1..2eb71bc 100755
--- a/tests/test_bugzilla2gitlab.py
+++ b/tests/test_bugzilla2gitlab.py
@@ -64,6 +64,9 @@ def mockmilestones(project_id, gitlab_url, headers, verify):
     # conf.gitlab_milestones is a dictionary
     assert isinstance(conf.gitlab_milestones, dict)
 
+    #conf.gitlab_skip_pre_migrated_issues is a boolean value
+    assert isinstance(conf.gitlab_skip_pre_migrated_issues, bool)
+
 
 def test_Migrator(monkeypatch):
     bug_id = 103
@@ -88,4 +91,9 @@ def mock_fetchbugcontent(url, bug_id):
 
     # just test that it works without throwing any exceptions
     client = Migrator(os.path.join(TEST_DATA_PATH, "config"))
-    client.migrate([bug_id])
+    assert (True, client.migrate([bug_id]))
+
+    # Test that the same bug is skipped if it's attempted to migrate again
+    conf = bugzilla2gitlab.config.get_config(os.path.join(TEST_DATA_PATH, "config"))
+    if(conf.gitlab_skip_pre_migrated_issues is True):
+        assert (False, client.migrate([bug_id]))
diff --git a/tests/test_data/config/defaults.yml b/tests/test_data/config/defaults.yml
index c9957d7..6d8c1cc 100755
--- a/tests/test_data/config/defaults.yml
+++ b/tests/test_data/config/defaults.yml
@@ -11,9 +11,9 @@ gitlab_base_url: "https://git.example.com/api/v4"
 verify: true
 
 # Auto-generate the issue id in Gitlab. If set to `true`, create a Gitlab issue with
-# the same id as the Bugzilla ticket number.  The group members which are 
+# the same id as the Bugzilla ticket number.  The group members which are
 # mapped in the user mappings need to be defined as project owners for this
-# to work properly. Otherwise the Gitlab API will silently ignore the `iid` setting 
+# to work properly. Otherwise the Gitlab API will silently ignore the `iid` setting
 # and fallback to the default behavior (i.e. auto-generate the issue id).
 use_bugzilla_id: false
 
@@ -76,3 +76,6 @@ map_milestones: true
 milestones_to_skip:
     - "---"
     - "UNKNOWN"
+
+# Set to true to skip pre-migrated issues
+gitlab_skip_pre_migrated_issues: true