We compared the antiemetic effect of dimenhydrinate with metoclopramide in patients who had undergone tyroidectomy. 40 patients were divided into two groups with 20 patients in each group. Group M (metoclopramide) received iv 10 mg and Group D (dimenhydrinate) received iv 50 mg dimenhidrat before induction. The nausea-vomiting score was not statistically different between the study groups. The incidence of nausea and vomiting in group M was found to be more frequent in comparison with group D, although it was not statistically significant. The need for additional antiemetics was less in Group D compared to Group M, but this was not statistically significant. There was no difference between the study groups regarding analgesic requirements and side effects. This study has shown that dimenhydrinate is as effective as metoclopramide for the prevention of postoperative nausea and vomiting in elective thyroidectomy patients.