Antiemetic activity of three protracted regimens for the control of cisplatin-evoked delayed emesis was explored. 63 patients were randomly assigned to receive one of three protracted antiemetic schedules over 4 days. Group C patients received dexamethasone 8 mg twice daily on days 2 and 3, then 4 mg twice daily on days 4 and 5; in group B, alizapride 2.5 mg/kg four times daily on days 2-5 plus dexamethasone as in group C was administered; and in group A, metoclopramide 0.5 mg/kg four times daily on days 2-5 plus dexamethasone was given at the same dose-schedule as in groups C and B. Complete protection from delayed vomiting was achieved in 44% of group C, 30% of B and 70% of group A (P = 0.02). Mild side-effects were noted in all three groups. A higher complete protection for delayed emesis was obtained in metoclopramide-dexamethasone-treated patients. Neither of the regimens used in the protection of delayed emesis controlled late nausea.