Abstract: Objective:To investigate the therapeutic efficacy of ondansetron combined with metoclopramide and vitamin B₆ on gastrointestinal reaction induced by chemotherapy of acute leukaemia.Methods:The patients with acute myeloid leukemia were intravenously injected 8 mg ondansetron and 100 ml of 5% GS 30 min before chemotherapy,and 20-30 mg metoclopramide,100-200 mg vitamin B₆ and 100 ml of 5% GS 4 hours after chemotherapy for 5 days.The patients with acute lymphoid leukemia were given ondansetron 30 min before chemotherapy at the same dosage as the patients with acute myeloid leukemia.The patients in control group were given 8 mg ondansetron and 100 ml of 5% GS 30 min before chemotherapy and 4 hours after chemotherapy.Results:The degree of nausea and antiemetic effect had no statistical difference between the two groups (P>0.05).Conclusions:The combined therapy of ondansetron,metoclopramide and vitamin B₆ has similar effect to repeated use of ondansetron on gastrointestinal reaction induced by chemotherapy of acute leukaemia.