Cisplatin and the combination of cisplatin, doxorubicin, and cyclophosphamide have documented activity in women with advanced or recurrent endometrial adenocarcinoma. However, response duration has been short and toxicity is substantial. To determine if similar activity could be obtained with less morbidity, we prospectively treated 33 patients with 360 mg/m2 carboplatin given intravenously every 28 days. Mean patient age was 69 years (range 40-86); all had a Zubrod functional status of 2 or less. Seventeen patients had advanced primary tumors, and 16 had recurrent disease. Prior treatment included surgical resection in 29 cases, hormonal agents in 7, and radiotherapy in 22. No patient had received prior chemotherapy. Mean treatment was 5.7 cycles. Nine of 27 patients (33%) with measurable disease had objective responses, including three complete and six partial responses. Nonresponders included 10 patients with stable disease and 8 whose disease progressed while on treatment. Median time to response was 3 months. Median progression-free survival for responders and nonresponders was 5 and 4 months, respectively. At analysis, 20 patients had died of disease, 7 were alive with disease, and 6 were clinically free of disease. Disease-free patients include 1 with a complete response and 5 who began treatment without measurable disease. Median follow-up for surviving patients was 18 months (range 4-32). Treatment toxic effects were minimal and largely limited to myelosuppression; 3 patients had grade 3 thrombocytopenia, 1 had grade 3 neutropenia, and 5 had grade 3 anemia. Carboplatin has define activity in endometrial carcinoma and offers a well-tolerated palliative therapeutic alternative.