OBJECTIVE: To review cases of endometriosis found at laparoscopy or laparotomy in women evaluated for infertility or recurrent abortion. DESIGN; Descriptive retrospective cross-sectional study. MATERIALS AND METHODS: 675 women with infertility or recurrent abortion underwent laparotomy or laparoscopy. PLACE: Human Reproduction Service National Hospital Edgardo Rebagliati Martins EsSalud. RESULTS: The prevalence of endometriosis was 47% (317 patients), being more frequent in women between 30 and 39 years. Endometriosis was minimal in seven cases (2.2%), mild in 101 (31.9%), moderate in 128 (40.4%) and severe in 81 cases (25.6%). In 38 cases one or more endometriosis was found. The most frequent location was posterior fornix, uterosacral ligament and the ovarian surface. It is also found in chronic salpingitis 26% (81 cases), with hydrosalpinges in 20 cases. They hatched 55 patients (17.4%...