Fifty-two patients with chemotherapy comprise cisplatin, adriamycin and dacarbazine underwent antiemetic therapy form September 1994 to June 1995. The chemotherapy regimens include CAP-VDS, ACO, EP, CHOP, AMF and MFP. The dose of PDD was 60-70 mg/M²,ADR was 40-50 mg/M² and DTIC was 300 mg/M². This study was the randomized, cross-over study, ruled out any differences between individual patients. Group A: Granisetron was given on the first day of chemotherapy, Granisetron 3 mg, Dexamethasone l0 mg i.v. at 30 minutes before chemotherapy; Group B: Ondansetron was given on the first and second days, Ondansetron 8 rag, Dexamethasone 10 mg i.v. at 30 minutes before chemo-therapy. The rates of complete control-free of vomiting were 80.8% and 82.7% in both groups respectively at 24 hours (P>0.05), 57.7% and 53.9% respectively (P>0.05)at second day, and 67.3% and 53.9% respectively (P<0.05) at third day. No difference was observed between both groups for the result of antiemetic control in seven days, the rate of overall control are 82.7% and 80.8% respectively (P>0.05). Adverse eventswith both antiemetic treatments were mild (essentially headache), the percentage of headache with ondansetron was 9.5% and granisetron 7.7%, constipation with ondansetron was 80.8% and granisetron 61.5%. Constipation: Granisetron, given as one i.v. 3 mg injection before chemotherapy plus dexamethasone, and ondansetron, given intravenously 8 mg injection before chemotherapy at the first 2 days plus dexamethasone are similar results on acute and dalayed chemotherapy induced vomiting in patients receiving their intensely emetogenic regimen.