BACKGROUND: Use of opioids to relieve postoperative pain may cause nausea and vomiting. There is growing interest in the use of nonpharmacologic approaches to the prevention of nausea. Particularly transcutaneous electrical nerve stimulation (TENS) of the P6 acupoint has been shown to reduce the incidence of pregnancy-induced nausea and chemotherapy associated emesis. The aim of this study was to investigate the effect of stimulation of the P6 acupoint on nausea induced by opioids for postoperative pain control. METHODS: We studied 103 patients receiving intravenous patient controlled analgesia (PCA) with fentanyl after a hysterectomy under general anesthesia. No antiemetic agent or device was provided in the N group (n = 31), and TENS on the P6 acupoint was applied after closure of the peritoneum in the T group (n = 32). In the P group (n = 39), a transdermal scopolamine patch was attached below the mastoid process about 1 hour before induction of general anesthesia. Incidence of nausea and pain score were assessed. RESULTS: The incidence of nausea was significantly less in the T and P groups than in the N group. There was no difference in the incidence of nausea between the T and P groups. The pain score was decreased in all three groups after beginning the PCA. No difference was seen in pain scores among the groups over the time course. CONCLUSIONS: TENS of the P6 acupoint reduced the incidence of opioid-induced nausea after a hysterectomy. This result suggests that TENS of the P6 acupoint may be useful as a new therapeutic approach to reduce or prevent nausea caused by opioids.