Forty consecutive eligible patients with advanced bronchogenic carcinoma and no prior chemotherapy were treated with a 5-drug combination of methyl-CCNU, cyclophosphamide, methotrexate, vincristine, and bleomycin. Of the 36 patients who completed at least one 6-week course of treatment and were considered evaluable, 4 (11%) had partial tumor response. Response by cell type was as follows: 2(14%) of 14 patients with squamous cell carcinoma, 2(18%) of 11 with oat cell carcinoma, and none of 11 with adenocarcinoma. Toxicity in the group of 36 evaluable patients consisted of nausea and vomiting in 24 patients (67%), severe leukopenia (white blood cell count less than 1000 cells/-mm3) in 7 patients (19%), severe thrombocytopenia (platelet count less than 100,000 platelets/mm3) in 14 patients (39%), and bleomycin pulmonary toxicity in 2 patients (6%). This combination does not appear to be more effective than single-agent chemotherapy for bronchogenic carcinoma.