This study elvaluated clinically the surgical results of the thirty-eight patients who had exploratory thoracotomy for spontaneous pneumothorax between Jan. 1989 and Nov. 1992. Thirty three, or 86.8%, of the patients were male. The most frequent age of the spontaneous pneumothorax requiring thoracotomy was between fifteen years and twenty years. Sudden onset dyspnea and chest pain, which developed in thirty-five patients[89.5%], were the major chief complaints. Bleb and Bulla located in the both upper lobes were the most frequent causes of spontaneous pneumothorax for exploratory thoracotomy. There was no operative death. Postoperative morbidity included three cases of residual air space in the apical pleural space, tow cases of atrial fibrillation, and one each case of reoperation for bleeding, mediasitinitis, and sternal osteomyelitis. All postoperative complications were treated without any serious problems. This study suggests that early exploratory thoracotmy is desirable for patients with prolonged air-leak, massive air-leak, or multiple blebs and giant bullae on the computed tomography of the chest