cis-Dichlorodiammineplatinum(II) (DDP), at a dose of 15 mg/m2/day x 5 consecutive days, was administered to 68 evaluable patients with metastatic soft tissue and bony sarcomas. All patients, except one, had received extensive prior chemotherapy and had had progressive disease at the start of the study. Responses observed included one complete response in a patient with mesothelioma and three partial responses in patients with soft tissue sarcomas (7%). No responses were seen in 18 patients with bony sarcomas. Significant leukopenia and thrombocytopenia were observed in less than 20% of evaluable courses, although two patients manifested life-threatening leukopenia (less than 1000 cells/microliter) and three had life-threatening thrombocytopenia (less than 24,000 cells/microliter). Nephrotoxicity was noted in less than 25% of evaluable courses. Nausea and/or vomiting was recorded in 55% of evaluable courses. DDP is considered to be marginally active in the secondary treatment of metastatic sarcomas at this dose and schedule. Further studies of DDP in mesothelioma are indicated.