We report on a 74-year-old woman who presented with embolic stroke of the brainstem and right cerebellum. She had undergone coronary bypass surgery and prophylactic ligation of the left atrial appendage in the past. On further investigations, a source of emboli was found to be an incompletely ligated left atrial appendage. Anticoagulation with warfarin if started after surgery would have reduced the risk of embolism in this patient.