Background: Spontaneous pneumothorax patients with blebs or bullae are considered to be good candidates for operation, and various objective diagnostic modalities have been performed for detection of blebs and bullae. This study was performed to compare the efficacy of thoracoscopic examination with using a minimally invasive 2 mm thoracoscope with high-resolution computed tomography (HRCT) for treating primary spontaneous pneumothorax. Material and Method: From June 2001 to March 2002, 34 patients with spontaneous pneumothorax undewent study with 2 mm video-thoracoscopic examination and HRCT. We regarded a blob larger than 5 mm in diameter as significant. Standard thoracoscopic wedge resection was performed in 18 patients with significant blob via a 2 mm video-thoracoscopic examination. 1 patient incurred bleeding, and the remaining 15 patients were treated with pleural drainage. Result: Multiple or single blob lesions were detected by 2 mm video-thoracoscope in 52.9% (18/34) of the patients with primary pneumothorax. For a total of 19 patients who were operated on, the diagnostic accuracy of the 2 mm video-thoracoscopic examination for bullae and blob was 94.7% (18/19), which was superior to that of HRCT (73.7%, 14/19). At a mean follow-up of $30{pm}3$ months, no recurrence occurred in both the operative group and the non-operative group. Conclusion: 2 mm video-thoracoscopic examination under local anesthesia has higher diagnostic accuracy than HRCT, and it is a useful alternative for determining the operative indications for spontaneous pneumothorax.