The purpose of this quasi-experimental study was to examine the effect of acupuncture on postoperative pain in day surgery patients undergoing arthroscopic shoulder surgery. Twenty-two participants scheduled to undergo arthroscopic shoulder surgery were included. The results showed that on postoperative day one pain decreased (-1.1) in patients receiving acupuncture compared to the control group in which pain increased (2.0), p=.014. Sleep quality was also significantly higher in the acupuncture group compared to the control group, p=.042. In conclusions, acupuncture seems to have a reducing effect on postoperative pain as well as increase sleep quality in day surgery patients undergoing arthroscopic shoulder surgery. In regards to application, nurses should be encouraged to use additional nonpharmacologic approaches like acupuncture in postoperative pain management, as this can be a part of the multimodal analgesic regimes to improve patients care.