Abdominal wall endometriosis is the development of endometrial tissue in the anterior abdomen usually due to an operation in which the uterus is manipulated. We herein delineate the presentation, clinical investigation, and surgical treatment of an abdominal wall endometriosis case. A 42-year-old female presented with acute abdominal pain in the lower quadrants in the margins of an old cesarean scar. Two masses in the abdominal wall highly suspected of consisting of endometrial tissue were found during the investigation of the patient. These ones were removed in surgery and endometrial tissue secondary to previous cesarean section was confirmed after histological analysis. Consequently, although rare, if a painful mass in a surgical scar, such as a Pfannenstiel incision, is found in women of reproductive age with a history of obstetric surgery, the differential diagnosis shall include endometriosis. There is a portion of cases in which endometriosis recurs within five years following conservative surgery.