Fifty-three patients, 17 with stage IIIB and 36 with stage IV non-small-cell lung cancer, were given CODE (cisplatin, vincristine, doxorubicin, and etoposide) plus antibiotic prophylaxis and an antiemetic regimen in an intensive chemotherapy program emphasizing weekly treatment and a planned brief duration (9-12 weeks); for 45 of these patients, the CODE program also included antifungal prophylaxis and supportive corticosteroids. Of the total study population, 33 patients (62%) responded to treatment, including five (9%) with complete response. The median survival for the entire group was 42 weeks (55 weeks for those with stage IIIB and 39 weeks for those with stage IV). More than 40% were alive at 1 year. Comparison of granulocyte counts of patients receiving prednisone with those of the subgroup to whom no corticosteroids were given showed less granulocytopenia for those receiving prednisone. Use of prednisone thus allowed improved delivery of myelosuppressive drugs. CODE was halted in nine patients because of disease progression. Although more constitutional side effects are associated with weekly chemotherapy than with standard chemotherapy, only 12 of the remaining 44 patients (27%) failed to receive at least 9 weeks of treatment. Serious toxicity was uncommon: There were no treatment-related deaths and only three episodes of neutropenia with fever. CODE is a novel treatment for non-small-cell lung cancer that this pilot study provided entirely in an outpatient setting over a 9-12 week period with an acceptable incidence of toxicity and a promising level of efficacy. Additional testing and comparison with other regimens or supportive care alone are warranted.