The risk factors that prolong length of stay of ambulatory patients can be classified as preoperative, intraoperative, and postoperative. Preoperative factors include the type of surgery, ear, nose and throat and strabismus surgery, old age and pre-existing congestive heart failure. Intraoperative factors include increasing length of surgery, and general anesthesia, while postoperative factors include postoperative nausea and vomiting, excessive pain and adverse cardiovascular events. The factors that anesthesiologists can address to reduce length of stay are postoperative nausea and vomiting and excessive pain. Multimodal management of postoperative nausea and vomiting and pain can minimize adverse events and thereby reduce length of stay in the postanesthetic care unit, but will not necessarily lead to a reduction in staffing levels. As personnel costs contribute the majority of postanesthetic care unit costs, more than 95%, direct financial savings may not be possible from eliminating adverse events alone. Optimizing the use of the postanesthetic care unit and reducing total hours in the unit with higher operating room turnover may lead to indirect financial benefits.