Postoperative nausea and vomiting is defined as any nausea, retching, or vomiting occurring during the first 24-48 h after surgery in inpatients. Postoperative nausea and vomiting is one of the most common causes of patient dissatisfaction after anesthesia, with reported incidences of 30% in all post-surgical patients and up to 80% in high-risk patients. In addition, postoperative nausea and vomiting is regularly rated in preoperative surveys, as the anesthesia outcome the patient would most like to avoid. While suture dehiscence, aspiration of gastric contents, esophageal rupture, and other serious complications associated with postoperative nausea and vomiting are rare, nausea and vomiting is still an unpleasant and all-too-common postoperative morbidity that can delay patient discharge from the post-anesthesia care unit and increase unanticipated hospital admissions in outpatients.