With the increase in the number of cesarean section operations, we started to face a new diagnosis, which is a cesarean scar defect, a defect in the uterine wall occurs as a result of the incomplete healing of the uterine wall after cesarean section, which can cause menstrual irregularity, inguinal pain and infertility in patients. The diagnosis of cesarean scar defect, isthmocele, niche is made by ultrasonography and hysterosalpingography, sonohysterography and hysteroscopy. Treatment is done by hysteroscopy or laparoscopy, depending on the residual thickness of the uterine wall at the niche site.