Spontaneous pneumothorax is a common surgical problem and occurs most frequently in male patients under 40 years of age. The records of 336 cases in 269 patients, diagnosed and treated as spontaneous pneumothorax during the period of 1981, Jan.- 1987, Dec., at the department of thoracic and cardiovascular surgery, college of medicine, Hallym university, were reviewed retrospectively. The results were as follows; 1. Spontaneous pneumothorax was commonly found between the age of 20-40[55%]. 2. Sexual ratio of male to female was 4.4:1. 3. The most common symptoms were dyspnea and chest discomfort or chest pain. 4. Pulmonary tuberculosis was the most common cause of the disease[30.8%]. 5. Recurrent rate after closed thoracotomy drainage was 28.2%, and not recurred after operation. 6. Bullae or blebs were found most commonly at the apical segment of both upper lobes.