Aim:Patients undergoing elective neurosurgical procedures were observed to determine the therapeutic efficacy of two different dosages of palonosetron. Materials and Methods:Patients undergoing elective neurosurgical procedures were randomly allocated to one of three groups: control (n = 30), 0.05 mg palonosetron (n = 30), or 0.075 mg palonosetron (n = 30). At the start of the dura mater closure, the medicines were administered intravenously. Anesthesia was maintained with 1 MAC sevoflurane in a 50/50 combination of air and oxygen. The patients were observed for 72 hours after extubation for postoperative nausea and vomiting. Results:The 0.075 mg palonosetron group had considerably less nausea than the control group in the first 6 hours (P = 0.019). At 0–72 hours after surgery, the incidences of nausea, retching, and vomiting in the 0.075 mg palonosetron group were considerably lower than in the 0.05 mg palonosetron or saline groups (P 0.001). Conclusion:PONV was decreased more efficiently in the 0.075 mg palonosetron group than in the 0.05 mg palonosetron and control groups in neurosurgicalpatients.