BACKGROUND: Postoperative nausea and vomiting (PONV) is one of the most common adverse complications associated with anesthesia and after surgical procedures. PONV is related to patient dissatisfaction and can lead to several postoperative complications. This study aimed to examine the efficacy and safety of penehyclidine combined with antiemetics in preventing PONV. METHODS: We searched English databases (including PubMed, Web of Science, Ovid Medline, Embase and Cochrane Library), Chinese electronic databases (including China National Knowledge Infrastructure, Wanfang, VIP, and Chinese Biomedical Literature) and trial registry databases to find randomized controlled trials researching the clinical validity of penehyclidine combined with antiemetics for PONV. The retrieval time was up to January 2025, without publication date restrictions. Articles published in the English and Chinese languages were considered. The primary outcome was the incidence of PONV within and over 24 hours postoperatively. The secondary outcomes were the incidence of different severities of PONV, incidence of postoperative rescue antiemetic therapy and postoperative complications. Quality assessment was conducted with the Cochrane Collaboration's risk of bias tool and grading of recommendations assessment, development and evaluation method. Subgroup analyses were performed according to the postoperative observation period. Trial sequential analysis was performed to validate the reliability of the primary outcome. Publication bias was assessed by funnel plots and Egger's regression test. RESULTS: Sixteen randomized controlled trials comprising 1561 participants were included. Compared with the control group, penehyclidine combined with antiemetics provided a lower incidence of PONV (risk ratio [RR]: 0.65; 95% CI: 0.57-0.74; P < .00001; I2 = 11%; low quality), lower incidence of severe PONV over 24 hours postoperatively (RR: 0.29; 95% CI: 0.15-0.56; P = .0003; I2 = 0%; low quality), and a lower incidence of postoperative rescue antiemetic therapy (RR = 0.42, 95% CI: 0.26-0.69; P = .0006; I2 = 58%; low quality). However, it was associated with a higher incidence of dry mouth (RR: 3.10, 95% CI: 2.28-4.20; P < .00001; I2 = 19%; low quality), but did not increase the incidence of other anticholinergic-related complications (RR: 1.08; 95% CI: 0.91-1.28; P = .38; I2 = 2%; low quality). CONCLUSION: Compared with antiemetics, penehyclidine combined with antiemetics could provide better prevention efficiency for PONV, with lower incidence of PONV, lower incidence of severe PONV over 24 hours postoperatively and lower incidence of postoperative rescue antiemetic therapy.