BackgroundThe use of multimodal pharmacological prophylactic regimes has decreased postoperative nausea and vomiting (PONV) in general but it still occurs in over 60% of female patients after bariatric surgery. This study aimed to evaluate the efficacy of ST36 acupoint injection with anisodamine in prevention of PONV among female patients after bariatric surgery.MethodsNinety patients undergoing laparoscopic sleeve gastrectomy were randomly allocated to anisodamine or control group at the ratio of 2:1. Anisodamine or normal saline was injected into Zusanli (ST36) bilaterally after induction of general anesthesia. The incidence and severity of PONV were assessed during the first 3 postoperative days and at 3 months. The quality of early recovery of anesthesia, gastrointestinal function, sleep quality, anxiety, depression, and complications were also evaluated.ResultsBaseline and perioperative characteristics were comparable between two groups. In the anisodamine group, 25 patients (42.4%) experienced vomiting within postoperative 24 h compared with 21 (72.4%) in the control group (relative risk 0.59; 95% confidence interval 0.40–0.85). Time to first rescue antiemetic was 6.5 h in anisodamine group, and 1.7 h in the control group (P= 0.011). Less rescue antiemetic was required during the first 24 h in the anisodamine group (P= 0.024). There were no differences in either postoperative nausea or other recovery characteristics.ConclusionsThe addition of ST36 acupoint injection with anisodamine significantly reduced postoperative vomiting without affecting nausea in female patients with obesity undergoing laparoscopic sleeve gastrectomy.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00464-023-10037-6.