Seventy-two patients with advanced stage IIIB (42%) or stage IV (58%) non-small cell lung cancer (median age 57 years, Karnofsky PS 60-100) were treated with mitomycin C (6 mg/m2, day 1), ifosfamide (1500 mg/m2, days 1-3), and cisplatin (30 mg/m2, days 1-3) every 4 weeks. The objective response rate was 37% in the overall population; 50% in stage IIIB patients and 29% in stage IV patients. Twenty four patients achieved partial response (33%) and three patients achieved complete response. Despite this relatively high objective response rate, the overall median survival time was 32 weeks. The median survival was significantly better in stage IIIB patients (55 weeks) than in stage IV patients (25 weeks) (P = 0.003). MIP regimen was permanently suspended in 14 patients because of toxic events. Seventeen patients developed grade III or IV febrile neutropenia and two patients died from sepsis. Two patients experienced acute mitomycin peumonitis. Despite increased doses of cisplatin and ifosfamide, compared with the original description for MIC chemotherapy, with probably higher toxicity, no apparent increased response rate or median survival was observed in this study. The MIP regimen could be tested in a randomized trial in comparison with other administration plans in a comparable population.