Our understanding and management of chemotherapy-induced nausea and vomiting has progressed substantially in the past decade. We now have many effective single agents, which are even more beneficial when used in appropriate combinations. A new class of antiemetic agents, the serotonin antagonists, of which ondansetron is the first to be commercially available, promises significantly better control of the various emetic syndromes caused by cancer chemotherapy, with fewer side effects. This article summarizes the state of the art of antiemetic therapy.