['To assess the impact of a multimodal antiemetic protocol on postoperative nausea and vomiting (PONV) after Le Fort I osteotomy.', 'Consecutive patients undergoing Le Fort I osteotomy with or without additional procedures at a single academic institution were recruited as the intervention cohort for an institutional review board-approved prospective clinical trial with a retrospective comparison group. The intervention cohort was managed with a multimodal antiemetic protocol, including total intravenous anesthesia; prophylactic ondansetron, steroids, scopolamine, and droperidol; gastric decompression at surgery end; opioid-sparing analgesia; avoidance of morphine and codeine; prokinetic erythromycin; and fluids at a minimum of 25 mL/kg. The comparison group consisted of consecutive patients from a larger study who underwent similar surgical procedures before protocol implementation. Data, including occurrence of PONV, were extracted from medical records. Data were analyzed in bivariate fashion with the Fisher exact and Wilcoxon rank-sum tests. Logistic regression was used to compare the likelihood of nausea and vomiting in the 2 cohorts after controlling for demographic and surgical characteristics. A P value less than .05 was considered significant.', 'The intervention (n = 93) and comparison (n = 137) groups were similar in gender (58% and 65% female patients; P = .29), race (72% and 71% Caucasian; P = .85), age (median, 19 and 20 years old; P = .75), proportion of patients with known risk factors for PONV (P = .34), percentage undergoing bimaxillary surgery (60% for the 2 groups), and percentage for whom surgery time was longer than 180 minutes (63% and 59%; P = .51). Prevalence of postoperative nausea was significantly lower in the intervention group than in the comparison group (24% vs 70%; P < .0001). Prevalence of postoperative vomiting was likewise significantly lower in the intervention group (11% vs 28%; P = .0013). The likelihood that patients in the comparison group would develop nausea was 8.9 and that for vomiting was 3.7 times higher than in the intervention group.'] Does multimodal protocol reduce postoperative nausea and vomiting in patients undergoing Le Fort I osteotomy?