24 patients with good risk non-seminomatous germ cell tumours (GR-NSGCT) were enrolled in a phase II trial combining carboplatin (C) and etoposide (E). Carboplatin was given at a fixed dose of 450 mg/m2 at d2, and E 120 mg/m2, dl-3, every 4 weeks x 4 cycles (cy). Myelosuppression was the major toxicity with neutropenia grade 4 in 18 cy (19%) and grade 3 in 26 cy (27%). Thrombocytopenia grade 3 and 4 occurred in 7 and 1 cy, respectively. Responses included: 20 complete responses (CR) (83%) with 16 clinical CR and 4 pathological CR; 3 additional patients had complete surgical removal of residual disease (SRRD) with viable tumour (surgical CR); 1 patient progressed during C+E therapy. 5 of the 16 clinical CR relapsed, and all the 3 surgical CR progressed despite post-operative salvage chemotherapy. Adverse events occurred in 9 patients (37.5%; 95% C.I., 19-59%). After a median follow-up of 24 m (range 14 to 38) 4 patients had died [3 progressive disease (PD), 1 suicide while in CR], 3 were alive with PD, and 17 had no evidence of disease. No significant correlation between area under the curve values of carboplatin, overall treatment failure and the platelet nadirs was observed. We conclude that the efficacy of the C+E regimen as given in our protocol is inferior to the standard cisplatin-containing regimens. The low dose-density (D/I) of carboplatin could be responsible for the high failure rate.