BACKGROUND: Ambulatory surgery has the advantages of reduced demand for postoperative medications, faster recuperation, less disruption to personal life and reduced hospital costs. At present, 60-70% of surgery in North America is performed on an ambulatory basis. DSC (day-surgery center) was opened on March 1995 in our hospital. We want to introduce an experience in anesthesia for ambulatory surgery. METHODS: Ambulatory surgeries were reviewed from March 1995 to July 1996. Total ambulatory surgeries were 5,593 cases. The medical records of 1,816 patients who were anethetized by anesthesiologists for ambulatory surgery were an alyzed retrospectively (3,777 patients who were operated under local anesthesia were excluded). RESULTS: The rate of utility was 14.1% on March 1995 and 27.7% on January 1996. The mean rate of utility was 22.2% per month in DSC. The overall mean rate of delayed discharge for the period was 2.9% and the overall mean rate of admission for the period was 1.9%. The principal reasons for the both were requestion by surgeons without surgery and anesthesia-related complications. CONCLUSIONS: The increase of demands of patients for ambulatory surgeries, new technological developements for surgery and anesthesia and increased experiences of surgeons will stimulate the utility of day surgery center.