Thirty-seven patients with recurrent epithelial ovarian carcinoma were entered into a trial of tamoxifen therapy (10 mg BID) to determine the effect on long-term survival. Thirty-one patients were evaluable with follow-up ranging from 6 to 42 months since initiation of hormonal therapy. All patients were heavily pretreated with multiple chemotherapeutic regimens (median 3). There was 1 complete responder (3.2%), 2/31 (6.4%) had a partial response, 6/31 (19.3%) had stable disease, and 22/31 (71%) had progressive disease. Twenty-four patients are dead (23 from advanced carcinoma, 1 from cardiac causes); 5 patients are alive with disease; 2 patients are lost to follow-up. Median survival of nonresponders was 7 months versus 16 months for responders (CR + PR + stable disease) (P = 0.001 life table analysis). Of the 9 responders, 7 had poorly differentiated tumors (grades 3 or 4), and 2 had moderately differentiated tumors (grade 2). Eleven patients had estrogen and progesterone receptor studies (ER, PR). No correlation between response rate and receptor status was evident. We conclude that although significant disease regression is unlikely to result from tamoxifen therapy, there may be a subset of patients who can benefit from the cytostatic properties of hormonal manipulation.