['To determine the incidence of postoperative nausea and vomiting when a combination of ondansetron and promethazine is given prophylactically, and to ascertain the effect of postoperative nausea and vomiting on recovery room duration and patient satisfaction.', 'Prospective, randomized, placebo-controlled, double-blind study.', 'University-affiliated tertiary-care hospital.', '87 ASA physical status I and II adult patients scheduled for middle ear surgery.', 'Patients were randomly assigned to receive one of the following interventions intravenously: ondansetron 4 mg (Group 1), promethazine 25 mg (Group 2), ondansetron 2 mg plus promethazine 12.5 mg (Group 3, combination), or placebo (Group 4).', "Independent, study blinded observers recorded complaints of nausea and number of episodes of vomiting for 24 hours following the patient's first response to commands. All patients were contacted the day after discharge to inquire about nausea and vomiting. The awakening time, postanesthesia care unit and day surgery unit durations, opioid use, and side effects were recorded. At the end of the 24-hour period, the study blinded observers asked patients for an overall assessment of their global anesthesia experience using an 11-point scale. During the 24-hour period, the incidence of postoperative nausea and vomiting was reduced from 74% (placebo) to 39% (promethazine; p = 0.03) and 29% (combination; p = 0.003). Compared with placebo, the severity of vomiting was significantly less in the combination group (p = 0.04). The number of very satisfied patients correlated negatively with the incidence of postoperative nausea and vomiting (p < 0.0001) and with the severity of vomiting (p = 0.003)."] Does ondansetron/promethazine combination or promethazine alone reduce nausea and vomiting after middle ear surgery?