Surgery volume in ambulatory surgery centers (ASCs) has increased markedly in recent decades, especially for plastic and reconstructive surgical procedures. Cosmetic procedure complication rates range from 0.33% to 1.9% at ASCs. 1 State regulatory bodies have sought to limit procedure length at ASCs, citing the rationale that longer procedure duration may be associated with increased complication rates. In the United States, there are state-specific regulatory policies for ASCs. Pennsylvania limits surgery length to 4 hours, and Connecticut limits surgery length to 1.5 hours with a 4-hour recovery time. In 2009, an evidence-based safety advisory on patient selection and ambulatory surgery from the American Society of Plastic Surgery recommended a 6-hour maximum surgery length at ASCs. 2 Regulation of surgical procedure length is a contentious issue. Limited data suggest a link between length of surgery and risk profile among patients undergoing body procedures (eg, abdominoplasty and body contouring with high-volume liposuction). 3 This finding is consistent with known consequences of body composition, fluid administration, and postoperative recovery. The safety profile for facial plastic surgery differs from that of such body procedures because of differences in blood loss, fluid shifts, postoperative pain, mobility, and venous thromboembolic rates. We therefore conducted a systematic review to determine the association between facial plastic surgery duration and risk of complications. Methods | A literature search using the Medical Subject Heading search terms anesthesia, analgesia, anesthetics, plastic surgery , reconstructive surgery procedures, and ambulatory surgical procedures was conducted from January 1, 1969, to May 30, 2016, to identify articles published from 1969 to 2016 in PubMed, Embase, Cochrane Central, and CINAHL. Articles on patients younger than 16 years, articles on inpatient surgery, and non-English articles were excluded. Forty-one articles were identified for full review. Independent investigators reviewed articles and collected data on standardized forms following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (eAppendix in the Supplement). Articles were assessed for risk of bias using the Downs and Black scale.