We present 4 cases of endometriosis complicated by massive ascites from our institution and a review of 27 cases from the literature. In most of these patients, the presence of ascites with its related symptoms in association with pelvic masses suggested a neoplastic disease. However, a large proportion of these women had also classical manifestations of endometriosis, e.g., dysmenorrhea, cul-de-sac nodularities, and exacerbation of ascites and other symptoms during the menses. The response to hormonal therapy including GnRH agonists was often unsatisfactory. Repeat recurrences and severe complications required multiple laparotomies and thoracotomies for associated pleural and pulmonary involvement.