The incidence of endometriosis at the episiotomy site is quite rare. We have experienced two cases of perineal endometriosis over a 9 year period. The typical clinical history and local findings enable us to make the correct diagnosis of both cases. The treatment of choice is complete surgical excision of endometrial tissue and usually obtains permanent cure. A review of the English literature showed there were 66 cases reported previously. The possible pathogensis of endometriosis and various modality of treatment were also discussed.