Forty-four patients with small cell lung cancer were treated with an intensive chemotherapy induction program consisting of combination cyclophosphamide, Adriamycin, and vincristine rapidly alternating with combination cisplatin and VP-16 followed by prophylactic cranial radiotherapy. After chemotherapy induction and cranial radiotherapy, patients with limited disease received multiple-field radiotherapy consolidation to the primary tumor site and mediastinum using thoracic computed tomographic scanning for field planning, and patients with extensive disease received chemotherapy maintenance. Patients with limited disease in complete remission following radiotherapy consolidation received no further treatment unless disease recurred. It was found that cyclophosphamide, Adriamycin, and vincristine could be alternated with cisplatin plus VP-16 at two-week intervals in 80 percent of patients on an outpatient basis and that two thirds of patients achieved clinical complete remission after two courses of each regimen. Locoregional radiotherapy delivered via multiple fields was effective in increasing the complete remission rate in patients with limited disease and was well tolerated. The median survival time was 18.5 months in 24 patients with limited disease and 12.2 months in 20 patients with extensive disease. Four patients with limited disease who received chemotherapy induction and radiotherapy consolidation without maintenance chemotherapy and one patient with extensive disease remain alive and disease-free at more than five years.