In a 22-year period from 1962 to 1984, 51 patients with malignant lung disease had a sleeve resection performed. In 33 % of the patients, pneumonectomy was contraindicated because of limited lung function. The operative mortality was 8 %. Six per cent of the patients developed complications after the operation. The 5-year survival of the total group of patients was 30 %. Patients with lesions classified as stage 1 and stage 2 had the best prognosis, with a 5- and 10-year survival of 43.5 % and 27 %, respectively. In patients classified as stage 3 and stage 4, the 5- and 10-year survival was 20 %. A postoperative measurement of regional ventilation and perfusion indicated that the function of the remaining lung was presumably undisturbed by the operation. Also, the vital capacity and FEV 1 were only minimally reduced as a result of the operation. The amount of functional lung tissue spared by the operation compared to pneumonectomy was estimated to 39 %. Because of these functional results and the promising 5-year survival figures, we suggest that sleeve lobectomy should be the operation of choice for tumors localized to the upper lobe orifice involving the main bronchus.