Twelve patients thought to have gynecologic tumors subsequently were found to have lymphoma or leukemia. Eleven tumors involved the genital organs; one involved the retroperitoneal pelvic lymph nodes. A lymphoma originated in the genital tract in 7 patients, and secondary involvement occurred in 2 patients. One patient with a previously treated lymphoma and 1 with leukemia in remission developed ovarian tumors as the first sign of relapse. The difficulty in diagnosis, need for appropriate treatment, and prognostic importance of the genital organs affected are discussed.