Between August 1984 and January 1987, the Southwest Oncology Group (SWOG) registered 46 patients with metastatic sarcomas on SWOG 8465, a Phase II trial of high-dose cisplatin in patients with metastatic soft tissue sarcoma. Six patients were ineligible for the following reasons: poor performance status (two patients); ineligible diagnosis (three patients, two with Ewing's sarcoma of bone and one with metastatic chondrosarcoma); and evaluable but nonmeasurable disease (one patient with bone-only disease). Of the 40 fully evaluable patients, 34 had received prior chemotherapy; treatment was with cisplatin (40 mg/m2/d for 5 consecutive days). Cisplatin was mixed in 250 ml of 3% NaCl and hydrated with a normal saline solution at a rate of 250 ml/h, beginning 12 hours before the first dose of cisplatin was specified. The second treatment was given 3 weeks after the first, with all subsequent treatments given every 4 weeks. After three cycles of treatment, responding patients were treated at a cisplatin dose of 20 mg/m2/d for 5 consecutive days. Leukopenia was of Grade 3 or 4 in seven patients, whereas thrombopenia was of Grade 3 or 4 in eight patients. More severe myelosuppression was produced in patients who had received prior radiotherapy. A single case of reversible Grade 4 nephrotoxicity was produced; neurotoxicity was observed in 11 cases, but was of Grade 3 in only 2 cases. Of the 40 evaluable cases, six showed partial responses or no responses, for a major response rate of 15%. High-dose cisplatin has minor activity and major toxicity in the treatment of metastatic soft tissue sarcomas, and should be considered investigational.