The purpose of this study is to evaluate the impact of a check list on the rate of late cancellation, i.e. the day before or the day of the ambulatory surgery.

The checklist is administered to the patients by phone between 7 and 3 days before the surgery. Each item of the checklist is associated with a decisional algorithm that allows take care for patients in case of any problem.

Inclusion Criteria:

• Patient (adult or minor) for which ambulatory surgery is programmed in a multipurpose ASU
• Surgery under general anesthesia or loco
• Regional or neuroleptanalgesia3. Patient contacted by phone
• Patient does not oppose his participation in the study

Exclusion Criteria:

• Patient programmed for endoscopy in ASU non surgical
• Ambulatory surgery scheduled for orthogenic
• Ambulatory surgery scheduled for urgency
• Ambulatory surgery performed under local anesthesia