The efficacy of ifosfamide combination chemotherapy was studied in 164 patients, 94 with advanced testicular carcinoma and 70 with metastatic sarcoma. Ifosfamide was given at 40-60 mg/kg/day i.v. on five consecutive days every 3-4 weeks together with mesna prophylaxis with 8 mg/kg i.v. being used at 0, 4 and 8 h after ifosfamide administration. Of 70 sarcoma patients 57 were evaluable for response, of whom 49 had received prior chemotherapy. The overall response rate was 46% (26/57) including 3 complete (CR) and 14 partial remissions (PR). Ninety-four patients with germ cell tumours of the testis were treated. Of 16 seminoma patients 15 achieved CR or PR. Seventy-eight patients with nonseminomatous testicular cancer who had received previous chemotherapy were either treated with ifosfamide/etoposide (n = 63, remission rate: 30%) or ifosfamide/cisplatin (n = 15, CR + PR: 33%). These results indicate that ifosfamide alone or in combination is active in sarcomas, seminomas and teratomas and that further studies are warranted employing the drug in first-line regimens.