A cesarean scar can cause abnormal uterine bleeding including prolonged menstruation or postmenstrual spotting. Our patient showed massive uterine bleeding from a cesarean scar and needed blood transfusion for hemorrhagic shock. A cesarean section had only been performed once for delivery stop 9 years ago. Recurrent hemorrhage could not be controlled by conservative treatment, and we performed laparoscopic scar resection and repair. The abnormal uterine bleeding was successfully stopped, and the menstrual cycle was normalized after surgical treatment. We should be aware that even an uneventful cesarean section may have a risk of massive hemorrhage postoperatively as in the present case.