Forty patients with small-cell lung cancer (31 patients with limited-stage [LS] disease, and nine patients with extensive-stage [ES] disease but of good performance status) have been treated with an intensive therapy composed of carboplatin alternating with cisplatin, ifosfamide, and etoposide with vincristine on day 14 of each carboplatin cycle. A maximum of six cycles were administered at 3 weekly intervals after the cisplatin combination and 4 weekly after the carboplatin combination. Prophylactic cranial irradiation was given with the first cycle of chemotherapy and thoracic irradiation with the third cycle. The median nadir for neutrophils was 0.47 x 10(9)/L and for platelets, 40 x 10(9)/L. Chemotherapy dosages were not reduced in response to myelosuppression, but treatment was delayed to allow blood count recovery. Sixty-eight percent of patients received all six cycles of chemotherapy, and there were four deaths associated with treatment-related neutropenia. Twenty-eight patients (70%) achieved a complete response (CR) when assessed 1 month after the end of treatment, and a further five patients (12.5%) had a partial response (PR). Median duration of CR was 16 months and of PR, 8 months. Cerebral metastases occurred in 20% of all patients and was the apparent sole site of relapse in 11% of the CR patients. The median survival of the total group was 14 months with an actual 2-year survival of 30% and a minimum follow-up of 28 months.