Purpose: There are studies examining the effect of Chinese acupressure on postoperative nausea, vomiting, and retching, but there is no study examining the effect of Korean hand acupressure. The study was conducted to determine the effect of Korean hand acupressure applied after thyroidectomy on the number and severity of postoperative pain, nausea, vomiting, and retching. Design: An experimental study with a post-test control group design involving randomized groups. Methods: The study was conducted with 42 patients who underwent thyroidectomy between February 1, 2021 and June 1, 2022. Korean hand acupressure was applied to the intervention group for 3 minutes using mung bean seeds 30 minutes before anesthesia. The application was continued every 2 hours and terminated at the eighth hour after the surgery. Pain severity, the number severity of nausea, vomiting, and retching, antiemetic use, and Rhodes Nausea, Vomiting and Retching Index score were assessed at the 2nd, 6th, and 24th hours postoperatively. Findings: The number and severity of retching in the intervention group at the sixth hour postoperatively was significantly lower than the control group (P < .05). The number and severity of nausea in the intervention group at the 2nd, 6th, and 24th hours after the surgery, as well as the number and severity of vomiting and retching at the 2nd and 6th hours after the surgery, were found to be clinically significant compared with the control group. Conclusions: Korean hand acupressure was an effective nursing intervention for reducing the number and severity of retching at the 6th hour after thyroidectomy and also reduced the use of antiemetics.