BACKGROUND: Discharge after day-surgery can be delayed for postoperative pain in a video-assisted thoracic sympathicotomy (VATS). However, there seems to be no research about postoperative pain after a VATS. We examined the characteristics of patients and operative factors, and compared the severity of postoperative pain according to different anesthetics. METHODS: We examined the age, sex, obesity index, and pain tolerance in 194 VATS patients of ASA physical status 1 or 2. The patients were randomly divided into two groups each with 97 patients. Group P was anesthetized with propofol, and group E with enflurane. We measured the visual analog scale (VAS) score at 5 minute, 2 hours, and 6 hours after arrival at the recovery room. RESULTS: There was no difference in the VAS score according to age, sex, obesity index, or pain tolerance. The VAS score at coughing was significantly higher than at rest. The VAS score in group P was higher than group E, but there was no significant difference. The patients who had a complication of a pneumothorax had a significantly higher VAS score. CONCLUSIONS: Postoperative pain seems to be aggravated by remaining air within the thorax after VATS.