OBJECTIVES: When talking about day surgery we have to differentiate between minor and major ambulatory surgery. Ambulatory surgery enables the patient to stay in the hospital not more than a few hours, showing similar safety and efficacy than conventional surgery. The objective of this paper is to evaluate the results of an ambulatory surgery program.METHODS: Descriptive retrospective study of the results of the Ambulatory Surgery in a Urology Department, including 4185 patients in a four-year period, from January 1st 2003 to December 31st 2006.RESULTS: In the study period the global substitution rate was 83.6%. The hospital admission rate was 2.5%, most of which were early admissions. Major complications appeared in 26 patients (0.6%), being major bleeding the predominant one. Most complications were minor or mild, and pain at the site of the surgical wound was the most frequent problem found.CONCLUSIONS: The increase and continuous promotion of ambulatory surgery are more than justified. The high satisfaction among patients undergoing this type of surgery, with a very low number of complications registered, provides us with a valuable tool for health-care expenditure control.