During the 3rd International Congress on NeoadjuvantChemotherapy (Paris 1991) a complete symposium was devotedto chemically induced nausea and vomiting and to the valueof Ondansetron. This book comprises original articlesdealing with the different topics discussed during thissession. It provides fuller information on current practicein anti-emetic treatment during anti-cancerous chemotherapyand sets out the position of a new and important drug,ondansetron, in this pathology. Different internationalclinical studies made with ondansetron in various types ofpatients are analysed: specific studies in hematology or inpulmonary disease, evaluation against benzamide-corticoid asa combined reference standard, or further the additiveeffect of a corticoid combined with ondansetron. One articleis devoted to the use of the drug in children. Finally,recent programmes dealing with both the intravenous and theoral use of ondansetron are assessed. The last article dealswith the economic evaluation of the use of ondansetron. Thusthe reader will findhere a recent and uo-to-date review ofthe results and possible uses of ondansetron, now thepremier member of the class of 5 HT 3 antagonists, inchemically induced nausea and vomiting.