In this study, 237 cases of spontaneous pneumothorax experienced at the department of Thoracic and Cardiovascular Surgery, Kosin Medical College during from January 1986 to December 1990 were analysed retrospectively. 1. The ratio of male to female was 4.6: 1, predominent in male. The incidence of age group was highest as 36% between 21 and 40 years old. 2. The associated diseases of pneumothorax were 27 cases, in which pyothorax were 8 cases, and hydrothorax were 19 cases. 3. The site of pneumothorax was as follows: right side was 53%, left side was 45%, and both side was 2%, so right side was slight high. 4. The empolyed managements were as follows: bed rest with oxygen inhalation in 13 cases, closed thoracostomy in 155 cases, open thoracotomy in 69 cases. 5. The operative procedures of thoracotomy were as follows; simple pleurodesis in 2 cases, blebectomy & bullectomy in 38 cases, parietal pleurecttnny in 4 cases, segmentectomy in 12 cases, lobectomy in 9 cases. 6. The indication of open thoracotomy were as follows, recurrent history in 35 cases, contralateral pneumothorax history in 2 cases, continuous air leakage in 24 cases, bilateral pneumothorax in 2 cases, and visible blebs & bullaes on the chest X-ray in 6 cases. 7. The hospital duration after management was as follow, open thoracotomy in 13.2 days, closed thoracostomy in 22.4 days. The recurrent pneumothorax after closed thoracostomy was 25 cases, about 15%.