Objective: To evaluate the effectiveness of hysteroscopic coagulation in treating symptomatic post cesarean section scar defect. Design: Retrospective study, Case series Patients: Four patients with post cesarean section scar defect who experienced postmenstrual abnormal uterine bleeding were retrospectively analyzed. Intervention: Four patients were diagnosed with post cesarean section scar defect by a transvaginal ultrasonography. Hysteroscopic surgery was performed in four patients with monopolar coagulation of the vessels on the defect site. Intrauterine device was inserted immediately following the hysteroscopic surgery and oral contraceptive medication was applied for one month in three patients. Results: The average age of the patients was 39.5 years and the average parity was 2.5. Three patients had history of two previous cesarean deliveries and one patient had three previous cesarean section. Transvaginal ultrasonography was performed in all patients and revealed post cesarean scar defects. Three patients showed no additional uterine pathology and one patient had adenomyosis. The average size of the defect was 9.4 mm wide and 9.13 mm in depth. All patients experienced postmenstrual abnormal uterine bleeding for average of 14 days accompanied by vaginitis or menorrhagia in two patients. No complications were observed. Postmenstrual abnormal bleeding as well as accompanying symptoms associated with vaginitis and menorrhagia disappeared following hysteroscopic electrocoagulation of the scar defect. Conclusion: Hysteroscopic coagulation of the cesarean section scar defect is a simple method to successfully treat the symptomatic cesarean section scar defects. Intrauterine device followed by oral contraceptive can prolong the effect hysteroscopic management of the defect. Hysteroscopic treatment may serve as an alternative method to repair the cesarean section scar defect other than laparoscopic or vaginal approach.