Anti-emetic effects, safety and usefulness of Ondansetron given intravenously at 4 mg once daily for consecutive 3-5 days were investigated against nausea and emesis induced by non-platinum anticancer drugs. Efficacy rates in control of nausea and emesis were 59% (20/34 cases) and 68% (23/34 cases), respectively. The efficacy rate for inhibition of nausea and emesis, calculated based on the control of nausea and emesis, was 68% (23/34 cases). Adverse events (headache and constipation) were observed in 1 case and abnormal change in clinical laboratory findings (increase in eosinophil count) in another case. Out of 42 cases in which safety was evaluated, 41 (98%) cases were assessed as "no problem in safety." However, one case with side effect was assessed as a "Minor problem in safety." From the above, it was confirmed that Ondansetron injection exerted excellent inhibitory effects against nausea and emesis induced by non-platinum anti-cancer drugs, and this drug was a highly safe and useful anti-emetic.