Background: Postoperative nausea and vomiting (PONV), postanesthetic shivering and pain are common postoperative patient complaints that can result in adverse physical and psychological outcomes. Some antiemetics are reported to be effective in the management of postoperative pain and shivering, as well as PONV. We evaluated the efficacy of dexamethasone added to ramosetron on PONV, shivering and pain after thyroid surgery. Methods: One hundred and eight patients scheduled for thyroid surgery were randomly allocated to three different groups: the control group (group C, n = 36), the ramosetron group (group R, n = 36), or the ramosetron plus dexamethasone group (group RD, n = 36). The patients were treated intravenously with 1 and 2 ml of 0.9% NaCl (group C); or 2 ml of 0.15 mg/ml ramosetron plus 1 ml of 0.9% NaCl (group R); or 2 ml of 0.15 mg/ml ramosetron plus 1 ml of 5 mg/ml dexamethasone (group RD) immediately after anesthesia. Results: Incidence of nausea and the need for rescue antiemetics, verbal rating scale (VRS) 1 hour pain value, ketorolac consumption, and incidence of shivering were significantly lower in group R and group RD, than in group C (P < 0.05). Moreover, these parameters were significantly lower in group RD than in group R (P < 0.05). Conclusions: Combination of ramosetron and dexamethasone significantly reduced not only the incidence of nausea and need for rescue antiemetics, but also the VRS 1 hour pain value, ketorolac consumption, and the incidence of shivering compared to ramosetron alone in patients undergoing thyroid surgery.