From January 1980 to December 1984, 186 patients with non-metastatic primary adenocarcinoma of the lung were treated in 10 different French Cancer Institutes. All patients have a minimal 5-year follow-up. There were 19 Stage I, 58 Stage II, and 109 Stage III. Survival was correlated with treatment modality. Survival rates for patients treated with surgery (36 pts), surgery and radiotherapy (65 pts), or radiotherapy with or without chemotherapy (80 pts) were 44.7%, 28.5%, and 6%, respectively. In the group of patients who were operated on, local control rate was improved by adjunctive radiotherapy delivering more than 50 Gy in 5 weeks. The cumulative risk of developing distant metastasis was 37% at the end of the first year following diagnosis and 68% at 5 years. Stage of the disease, nodal involvement, and location of the primary were the main factors of prognosis.