Cisplatin is recognized as an active chemotherapeutic agent in a broad variety of human tumors. The severe emetic effects of cisplatin, however, result in both acute and delayed emesis syndromes causing considerable morbidity. Over the last decade, the standard of therapy for control of cisplatin-induced emesis has been high-dose metoclopramide. Unfortunately, approximately 30% of cisplatin-treated patients experience emesis despite metoclopramide-based combination antiemetic therapy. Further, metoclopramide itself is associated with side effects, in particular, extrapyramidal reactions that may lead to patient refusal of further chemotherapy. This review describes the current development status of a new class of antiemetics, the serotonin antagonists, that have demonstrated efficacy in preventing cisplatin-induced nausea and vomiting. In addition to a high degree of effectiveness, these agents are characterized by a low incidence of significant side effects and the complete absence of extrapyramidal reactions. Their introduction into clinical use should add substantially to the practicing oncologist's therapeutic armamentarium and improve the quality of life of patients treated with cisplatin.