Progestin therapy of ovarian carcinoma in the past has been reported to lead to varying response rates. A multicenter phase II study of high-dose MPA was conducted in 53 patients with epithelial ovarian cancer who had received adequate trials of conventional therapy with cytotoxic agents. Forty-one patients were included for response and toxicity evaluations. Only one partial response has been recorded with a duration of 20 weeks. Stabilization of disease was observed in 7 patients. The present investigation shows that MPA given at the present high dose is not effective in patients extensively pretreated with chemotherapy.