Abstract: A niche-shaped myometrium defect can be noticed after the cesarean procedure, which is defined as the thickness of the remaining myometrium < 3 mm or < 50% of the adjacent myometrium. The leading symptom of patients with cesarean scar defect is long-lasting spotting following a normal menstrual period; dysmenorrhea and infertility are relatively rare symptoms.Pregnancy in the niche of the cesarean scar and uterine rupture are much more severe complications happening in the conceived patients. The transvaginal sonography is most widely used for diagnosis due to its convenience and accuracy, which along with magnetic resonance imaging or hysteroscope provides more detailed information. The majority of patients have no symptoms and treatment is only indicated when there are symptoms that need to be corrected, particularly the spotting symptom. There are only a few of studies revealing that oral contraceptives could be used as a conservative treatment. Both thermo-ablation andcanalling are effective, but they should not be opted if a future pregnancy is expected. On the contrary, the laparoscopic or transvaginal repair of the defect is more promising. They both provide not only symptom correction but also improvement of the scar thickness.