To establish the effectiveness of oral 5-HT(3) antagonist, oral 5 mg tropisetron was introduced in the 21 cases with hematological malignancies for the prevention of chemotherapy-induced nausea and vomiting. Nausea and vomiting did not develop in 81% of patients receiving the tropisetron in this study. The results suggested that oral tropisetron is effective for the control of acute, and to a lesser extent, delayed, nausea and vomiting. The drug enhanced patients' quality of life and reduced the clinical cost. In conclusion, tropisetron is effective for the prevention of chemotherapy-induced nausea and vomiting in treatment for hematological malignancies. It is suitable as first-line therapy for outpatients.