In patients undergoing lung resections like lobectomy or bilobectomy, prolonged air leak is one of the major complications, which commonly exists with residual airspace.We performed 48 lung cancer lobectomy in the first 6 months of 1998. Out of those 48 patients, 14 patients’ remnant lungs failed to fill the hemithoracic cavity under 30 cm H2O pressure after resection. We applied perioperative pneumoperitoneum (pnp) to this subset of patients.Patients were analysed retrospectively according to age, gender, preoperative Forced Expiratory Volume in one second, coexisting diseases, the length of chest tube drainage 2034 cc. The mean length of the tube drainage was 2,18 days.Results showed that patients who had predisposing factors for prolonged air leak and air space did not have this complication, if the pneumoperitoneum procedure had been applied. The method seemed safe, cheap, effective and not time consuming.