Only a few studies have been carried out in children on the prevention of chemotherapy-induced acute emesis. 5-HT3 antagonists have been shown to be more efficacious and less toxic than metoclopramide, phenothiazines and cannabinoids. The optimal dose and scheduling of the 5-HT3 antagonists has not been identified. Combinations of a 5-HT3 antagonist and dexamethasone show increased efficacy with respect to 5-HT3 antagonists alone. All pediatric patients receiving chemotherapy of high or moderate emetogenic potential should receive a combination of a 5-HT3 antagonist and dexamethasone to prevent acute emesis. No studies have specifically evaluated antiemetic drugs in the prevention of chemotherapy-induced delayed and anticipatory emesis in children.