We conducted a Phase II study to determine the efficacy of cisplatin, doxorubicin, mitomycin C, and 5-fluorouracil in patients with untreated non-small cell lung cancer. Patients were accrued through the Connecticut Oncology Association (COA), an organization composed of community and university oncologists. Thirteen COA oncologists enrolled 30 patients over 12 months and 26 were eligible for the final analysis. Patients received cisplatin 75 mg/m2, doxorubicin 30 mg/m2, mitomycin C 6.5 mg/m2, and 5-fluorouracil 750 mg/m2 on day 1. The treatment was repeated every 4 weeks, with mitomycin C given during the first 3 cycles and then every other cycle. There were 5 (19%) partial responses, lasting 1.3-7.3 months. The median time to progression was 10.3 months (0.3-12.5 months). Median survival was 7.5 months (0.3-34 months). The major toxicities were related to myelosuppression and there was one septic death. This study demonstrates the limited efficacy of an aggressive regimen using "active" agents in patients with advanced non-small cell lung cancer.