Twenty-six women with advanced or recurrent endometrial cancer were treated with cisplatin at a dose of 50, 70, or 100 mg/m2every 4 weeks. An objective response was obtained in 11 of 26 patients (42%), with 10 partial responses and 1 complete response. The median duration of remission was 5 months, with a range of 2 to 11 months. The complete response lasted 8 months. Five patients had stable disease lasting an average of 5 months. One of 6 patients (16.6%) responded to cisplatin at a dose of 50 mg/m2, 4 of 7 (57%) responded to the dose of 70 mg/m2, and 6 of 13 (46%) responded to the dose of 100 mg/m2, but the differences were not statistically significant (P=.2). In 8 of 26 cases (31%) cisplatin was discontinued because of toxicity. Three patients developed a peripheral neuropathy, 1 patient refused further therapy because of vomiting, 2 patients had nephrotoxicity, and 2 others had both nephrotoxicity and neurotoxicity. The average total cumulative dose of cisplatin administered when renal deterioration and neuropathy occurred was approximately 500 mg/m2. Cisplatin is definitely active against endometrial cancer, but toxicity precludes its prolonged administration in high doses on an outpatient basis. By maintaining a forced diuresis, toxicity can probably be decreased, thereby permitting continued administration of cisplatin. The drug may also be more useful when used at a lower dose in combination with other active agents against endometrial cancer.