BACKGROUND: Postoperative nausea and vomiting (PONV) is common after tonsillectomy in children. There is evidence that perioperative acupuncture at the pericardium 6 (P6) point is effective for preventing PONV in adults. Our goal was to determine if intraoperative acupuncture at the P6 point, in addition to usual antiemetics, is more effective than antiemetics alone in preventing PONV in children. METHODS: In a randomized double-blind trial, 161 children age 3 through 9 years undergoing tonsillectomy with or without adenoidectomy were randomized to either bilateral acupuncture at P6 plus antiemetics (n = 86) or antiemetics only (n = 75). All participants received ondansetron 0.15 mg/kg and dexamethasone 0.25 mg/kg, up to 10 mg. The presence of nausea, retching, emesis and administration of additional antiemetics were recorded during phases I and II of PACU recovery. Follow-up calls occurred on postoperative day 1 (POD 1). RESULT: During phase I and II recovery, the incidence of PONV was significantly less with acupuncture than without (7.0% vs 34.7%, RR: 0.2, 95% CI: 0.09-0.46; P < 0.001). The difference in PONV was driven by less nausea in the acupuncture group (5.0% vs 24.0%), with no difference in vomiting between the two groups. In the first 24 hours, PONV occurred in 36.1% with acupuncture and 49.3% without; these values did not differ significantly (P = 0.09). CONCLUSIONS: Children receiving acupuncture plus antiemetic therapy had less risk of developing nausea during phase I and II recovery, but there was no difference in PONV on POD 1. Acupuncture may reduce nausea in the PACU, even when combined with antiemetics.