With approximately 40 cases on record, it is apparent that endometriosis at the site of episiotomy scar is quite a rure occurrence. This study deals with 15 cases observed personally and drawn from a series of 2028 consecutive deliveries. After the placenta had been removed each of the patients in this series had been submitted to endometrial curettage as a routine measure to prevent postpartum bleeding and uterine subinvolution. During the same period, 13,800 additional women were delivered in the same service. In this series, also, an episiotomy was carried out almost regularly but the patients were not curetted after delivery. In this group, not a single case of perineal endometriosis occurred. The question of fortuitous circumstances as against causal relationships between postpartum endometrial curettage and perineal endometriosis is discussed and possible pathogenetic mechanisms are analyzed.