Relatively few instances of surgical scar endometrioma have been reported. Herein we review 24 patients treated for this condition at the institutions at which we work between 1972 and 1992. The age of the patients ranged from 17 to 47 years, with an average age of 31.7 years. Surgical scar endometriomas occurred after operations including cesarean section (19 patients), appendectomy (two patients), episiotomy (two patients) and hysterectomy (one patient). The interval between prior surgical treatment and the onset of symptoms ranged from one to 20 years, with an average of 4.8 years. All patients were treated by wide excision. Seventeen of 24 patients were available for follow-up evaluation. The interval between excision and follow-up evaluation ranged from 1.2 to 14.0 years, with an average of 6.4 years. None of the patients had recurrence of surgical scar endometrioma. Patients with the classic presentation of a painful surgical scar mass that increases in size or tenderness during menstruation need no further evaluation of the lesion before excision. Ultrasonographic examination and fine needle aspiration biopsy should be used preoperatively in women who have a constantly painful or asymptomatic mass in a surgical scar. Because medical management yields poor results, wide excision of surgical scar endometriomas is the treatment of choice.