BACKGROUND: Acupuncture has been used to supplement opioid analgesics for postoperative pain control. We designed this double-blind, sham-controlled study to assess the effectiveness of capsicum plaster (PAS) at Zusanli (ST-36) acupoints on postoperative opioid analgesic requirement, side effects, and recovery profile. METHODS: Ninety women undergoing total abdominal hysterectomy were randomly assigned to 3 treatment regimens (n = 30 each): group Zusanli = PAS at Zusanli acupoints, group sham = PAS at the nonacupoints on the shoulders, and group control = placebo tape at Zusanli acupoints. The PAS was applied before induction of anesthesia and maintained for 8 h per day for 3 postoperative days. RESULTS: The total amount of morphine administered in the first 24 h after the operation was significantly decreased in group Zusanli (31.5 +/- 6.8 mL) compared with groups control (44.3 +/- 10.1 mL) and sham (44.6 +/- 10.4 mL) (P < 0.01). The incidence of postoperative side effects and the use of rescue antiemetics during the 72 h after surgery were significantly reduced in group Zusanli compared with other groups (P < 0.01). CONCLUSION: PAS at Zusanli points decreased the postoperative opioid requirement and opioid-related side effects of patients undergoing abdominal hysterectomy.