Endometriomas have been described in various operative scars. Those following cesarean section have been considered rare, with 90 cases previously reported. This study is a retrospective analysis of 14 such cases diagnosed between 1985 and 1990 at Grady Memorial Hospital, Atlanta, Georgia. Fourteen of 16 cases (87.5%) of scar endometriosis followed cesarean section, representing an incidence of 1.9 cases of scar endometriosis per 1000 cesarean sections performed. Historical features included pain, an enlarging mass, bleeding from the incision, and characteristic exacerbation of symptoms with menses. Examination usually showed a discrete, tender mass in or near the incision, with discoloration of the overlying skin. Although certain operative indications, techniques, and complications have been postulated to predispose a patient to developing scar endometriosis, no specific risk factors were identified in our cases. The diagnosis usually was made from the history and physical examination, and excision was the treatment of choice, resulting in a cure rate of 100%.