Purpose: The study was done to investigate the effect of ethanol inhalation on postoperative nausea in patients using Patient Controlled Analgesia (PCA). Methods: The data were collected from June 1st 2006 to September 30th, 2007. The subjects were 70 patients who had had orthopedic surgery under general anesthesia. The levels of the Visual Analogue Scale (VAS) was used to measure postoperative nausea. The experimental group was given ethanol inhalation using ethanol pads and the control group received normal saline pads. All participants were instructed to take two deep sniffs with the pad one inch from the nose. This was repeated every five minutes for three doses. The collected data were analyzed using SPSS/WIN 12.0 program. Results: The study supported all hypotheses. "The experimental group given first dose of ethanol inhalation would have a lower level postoperative nausea compared to the control group"(t = -5.900, p = .000). "The experimental group given second doses of ethanol inhalation would have a lower level postoperative nausea compared to the control group"(t = -7.507, p = .000). "The experimental group given third doses of ethanol inhalation would have a lower level postoperative nausea compared to the control group"(t = -6.685, p = .000). Conclusion: According to these results, the ethanol inhalation can be considered an effective nursing intervention for relieving the postoperative nausea in patients using PCA.