Background: Postoperative vomiting is a common complication after strabismus surgery in children. The serotonin 5-HT 3 receptor antagonists have proven to be a particularly valuable addition to the armamentarium against postoperative nausea and vomiting (PONV). Palonosetron is a secondgeneration 5-HT 3 receptor antagonist that has recently been approved for prophylaxis against PONV. Objective: The aim of this study was to evaluate the efficacy of different doses of palonosetron for the prevention of PONV in children undergoing strabismus surgery. Patients and Method: A total of 150 children who were classified with an American Society of Anesthesiologists physical status of I, were aged between 2 and 12 years, and were undergoing strabismus surgery under general anesthesia were enrolled in the study. A random numbers table was used to assign each child to receive palonosetron 0.5, 1.0, or 1.5 mg/kg (n = 50 in each group). All episodes of PONV at the intervals of 0-2, 2-6, 6-24, and 24-48 hours were evaluated using a numeric scoring system for PONV. A p-value of <0.05 was considered statistically significant. Results: The percentage of children with PONV during 0-48 hours after anesthesia was 24% with palonosetron 0.5 or 1.0 mg/kg, and 20% with palonosetron 1.5 mg/kg. There was no statistically significant difference between the study groups with respect to the number of children with PONV scores of 1, 2, or 3 during 0-48 hours after anesthesia. There was no statistically significant difference between the study groups with respect to the number of children with postoperative vomiting during all time periods after anesthesia. The percentage of children aged >6 years with postoperative nausea during 0-48 hours after anesthesia was 8.6%, 18.2%, and 15.4% with palonosetron 0.5, 1.0, or 1.5 mg/kg, respectively, but there was no statistically significant difference between the study groups.