Hyperfractionated split course radiotherapy combined with carboplatin, etoposide and mitomycin C was administered to 76 patients with stage III non-small cell lung cancer. Grade 4 leukopenia occurred in 5 patients; 4 toxic deaths were observed. The overall response rate was 45%, including a 9% rate of complete responses, which lasted > 12 months in four cases. The median survival was 13 months, 2-year progression-free survival 17%, actuarial 2-year survival rate 22%. Age > 65, performance status > 1, no response to prior treatment were predictors of poor outcome. Our treatment plan, particularly because of the long lasting complete responses, warrants further investigation.