Twenty-three patients with advanced or recurrent endometrial carcinoma entered a prospective study of chemotherapy which consisted of carboplatin (300 mg/m2), methotrexate (30 mg/m2), and 5-fluoruracil (500 mg/m2) given on day 1, in a 3-weekly schedule, in combination with medroxyprogesterone acetate (MPA): 300 mg daily, p. o., until progression (JMF-M regimen). None had received prior chemotherapy and/or hormonotherapy for metastatic disease. Ten patients had received radiotherapy. Response to treatment was evaluated every two courses. Objective response was seen in 17 of the 23 patients (74%, 95% confidence interval = 52-90%), with 2 long-lasting complete responses (9%). The median response duration was 10+ months (3-45+). The median survival was 16+ months (2-45+). The 2 complete responders, the first in the lung and the second in groin nodes, are without evidence or recurrence after 32 and 45 months, respectively. The regimen was given on an outpatient basis and was well tolerated. The major toxic effects were myelosuppression (less than 14% leukopenia, anemia and thrombocytopenia). The MPA-related side effects were: weight gain (22%), hypertension (17%) and thromboplebitis (17%). In 2 patients, consolidation treatment with MPA was discontinued because of thromboplebitis. In conclusion, the JMF-M regimen is highly active with an acceptable toxicity in patients with recurrent or metastatic endometrial carcinoma.