In 1980, 27 patients with inoperable lung cancer (26 non-oat cell, one oat cell) were treated by split-course irradiation (40 Gy/10 fractions) plus concomitant low-dose chemotherapy (doxorubicin 10 mg/m2). Twenty-four of the 27 patients received the entire treatment course. Fifteen of the 27 patients were administered various chemotherapy protocols after a period of one month. Median survival was 16 weeks despite a 60% response rate. The lungs were the main site of complications (13 cases of radiation pneumonitis for the 24 patients), which occurred primarily when an objective response was obtained. These complications partially explain the poor results. Injection of doxorubicin during irradiation appears to have been a determining factor.