 Patients were informed on how to use the patient controlled analgesia device during the postoperative period. The risk criterias for PONV were recorded for each patient.Patients were randomly assigned to two study groups of 30 patients. All patients were premedicated with intravenous iv midazolam 1-2 mg. On arrival in the operating room, standard anesthetic monitors were applied. Anesthesia was induced with iv propofol 2-3 mgkg and fentanyl 1-1.5 μgkg. Tracheal intubation was facilitated with rocuronium 0.6 mgkg. After tracheal intubation all patient received iv 8 mg dexamethasone. Normocapnic mechanical ventilation was performed after intubation. General anesthesia was maintained with sevoflurane 1 minimum alveolar concentration in oxygen air mixture and remifentanil 0.1-0.3 μgkgmin infusion.Four mg ondansetron and for each patient 1 mgkg dimenhydrinate in the 5 ml syringe solution were prepared by pharmacy department, and given to the blinded investigators. The patients, anesthesiologists with the exception of the primary author, statistician, and observes were all blinded. 