The peritoneal washings obtained at diagnostic laparoscopy of two women with suspected endometriosis contained cells with cytologic features of adenocarcinoma. Exploratory laparotomy, total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and pelvic washings confirmed endometriosis with no evidence of cancer. At 1.5-year and 4.0-year follow-up, respectively, cancer had not developed in either patient. The authors report what they were able to find in the literature regarding false-positive assessments of malignancy obtained by cytologic examination. They also outline steps to be taken should a diagnosis of malignancy arise in a woman with endometriosis who desires pregnancy.