Delayed emesis has been arbitrarily defined as vomiting and/or nausea beginning, or persisting for, more than 24 h after chemotherapy administration. Acute emesis is the most important prognostic factor for delayed emesis. Owing to the relatively high incidence and severity all patients treated with cisplatin > or = 50 mg/m(2) should receive antiemetic prophylaxis. In these patients a combination of dexamethasone plus metoclopramide or a 5-HT3 antagonist is the most efficacious regimen. All patients submitted to moderately emetogenic chemotherapy, such as cyclophosphamide, carboplatin, doxorubicin and epirubicin, should also receive antiemetic prophylaxis with oral dexamethasone to prevent delayed emesis.