Ambulatory surgery has been organized and regulated in France since 1991. We report the organisation of this activity in our unit and the results in 22,476 patients. Endoscopies, not specifically surgical, were 25.7% of procedures. Over night hospitalization was needed in 3.1% of patients, including about 40% of them for social and familial conditions or follow up of diagnosis or therapeutic sequences. This rate is growing, because we developed diagnosis or therapeutic sequences for interest of the patient. Since 1994, we operated more patients in ambulatory surgery than in classical hospitalization.