Delayed emesis is a distinct syndrome where vomiting begins or persists 24 or more hours after chemotherapy. It is more likely to occur when the stimulus for emesis is strong and/or acute vomiting is poorly controlled. The pathophysiology appears different than that which causes acute emesis. The literature reporting clinical trials to prevent delayed nausea and vomiting are presented. The best ways of preventing delayed emesis following anticancer chemotherapy are discussed.