The emetic profile of action of cisplatin 5 and 10 mg/kg i.p. was investigated in the ferret over a 72 and 24 hr period respectively. The 5-HT3 receptor antagonists ondansetron and alosetron markedly antagonized or abolished the emesis during the "acute phase" and, whilst antagonizing the emesis during the delayed phase, also revealed a 5-HT3 receptor antagonist resistant component. These cisplatin paradigms may provide models relevant to the study of acute and delayed emesis induced by cisplatin in man.