['Postoperative nausea and vomiting (PONV) are common complications after gynecological laparoscopic surgery. Because monotherapy with antiemetics is insufficient, combinations of various antiemetics are often recommended by experts. In this study, our purpose was to find out whether penehyclidine could enhance the efficacy of tropisetron in preventing PONV.', 'With hospital ethics committee approval, we investigated 120 women undergoing gynecological laparoscopic surgery receiving prophylactic tropisetron (0.1\xa0mg/kg; maximal dose, 5\xa0mg) (group T) or tropisetron (0.1\xa0mg/kg; maximal dose, 5\xa0mg) plus penehyclidine (0.01\xa0mg/kg; maximal dose, 1\xa0mg) (group TP), or penehyclidine (0.01\xa0mg/kg; maximal dose, 1\xa0mg) (group P). The incidence of vomiting, the intensity of nausea (assessed by a visual analogue scale [VAS]), antiemetic rescues, and adverse effects were recorded at 2, 6, 12, and 24\xa0h after surgery in the gynecological ward by a visiting nurse anesthetist who was unaware of the treatments. Collected data were analyzed using analysis of variance (ANOVA) and the χ(2) test. Continuous variables were expressed as means\xa0±\xa0SD, and non-continuous variables were expressed as n (%).', 'The overall incidence of vomiting was 28.3\xa0% (34/120) in our study. The incidence of vomiting was significantly lower in group TP (4 cases, 10\xa0%) than that in group T (12 cases, 30\xa0%) and group P (18 cases, 45\xa0%). The incidence of vomiting in group TP was also significantly lower than that in group T at 0-2\xa0h and 2-6\xa0h postoperatively and it was also significantly lower than that in group P at 0-2\xa0h, 2-6\xa0h, 6-12\xa0h, and 12-24\xa0h postoperatively. The incidence of vomiting was significantly lower in group T than that in group P at 12-24\xa0h postoperatively. The VAS of nausea was significantly lower in group TP than that in group T and group P at 2 and 6 h after surgery. It also showed a significant higher score in group P than that at group T and group TP at 12 and 24 h. Within group P, the VAS of nausea was significantly lower at 2 h postoperatively than that at 24 h.'] Does penehyclidine enhance the efficacy of tropisetron in prevention of PONV following gynecological laparoscopic surgery?