Intrapleural instillation of a chemical irritant (chemical pleurodesis) is an effective way to shorten the duration of air leaks and reduce the rates of recurrent spontaneous pneumothorax in surgical and non-surgical patients. Many chemical irritants (tetracycline, talc, and minocycline) have been used to decrease the rate of recurrence in spontaneous pneumothorax. Tetracycline, which was the most commonly used irritant, is no longer available. Talc insufflation of the pleural cavity is safe and effective for primary spontaneous pneumothorax. However, it should be applied either with surgical or medical thoracoscopy. Minocycline, a derivative of tetracycline, is as effective as tetracycline in inducing pleural fibrosis in rabbits. In the previous studies, we have shown that additional minocycline pleurodesis is a safe and convenient procedure to decrease the rates of ipsilateral recurrence after thoracoscopic treatment of primary spontaneous pneumothorax. In the present study, additional minocycline pleurodesis will be randomly administered in patients with first episode of primary spontaneous pneumothorax after simple aspiration. The primary goal is to test if intrapleural minocycline can reduce the rate of recurrence. The secondary goals are to evaluate the safety profile, short-term results, and long-term effects of minocycline pleurodesis after simple aspiration. The sites of study include National Taiwan University Hospital and Far Eastern Memorial Hospital. A total of 300 patients (150 patients in each arm) will be included for this study.