A pneumothorax usually occurs in young men. From the cosmetic point of view, the size of the skin incision should be considered to be minimal if surgery is applied for young pneumothorax patients. We reported a case of pneumothorax which was operated with a small longitudinal axillary skin incision, the size of which was 3.5 cm long. The patient was a 18-year-old high school student. He was admitted to our hospital with the diagnosis of spontaneous pneumothorax. His chest X-ray showed a moderate collapse of his left lung and bullae in his left apex. Tube drainage was performed and the collapsed lung re-expanded completely. Chest CT scan demonstrated that he had bullae in the apex of his left lung. No other lesions were found in the other part of both lungs. Surgery was indicated socially. Bullectomy was successfully performed with a small (3.5 cm) longitudinal axillary skin incision. We recommend this skin incision for young patients with pneumothorax if the chest CT scan confirms that the bullae or blebs are localized to the apex of superior segment of the lower lobe.