In this study we compared two methods of granisetron administration. One method was via a drip infusion with 100 ml of normal saline 30 minutes prior to administration of CDDP (Group A). The other method was direct injection of granisetron into the CDDP containing bottle (Group B). By employing a randomized cross-over method, we evaluated the acute response (less than 24 hours) according to Furue's criteria in 34 patients. Each of the patients received more than two cycles of chemotherapy containing more than 50 mg of CDDP. In both arms of the study nausea, vomiting and anorexia showed no difference. Moreover, there was no evidence of toxicity due to granisetron. The overall response rate of granisetron to nausea was 84.4%. We conclude that granisetron is an effective drug as an antiemetic, and the direct injection of granisetron into the CDDP containing bottle has the same effect when compared to the normal method of administration, together with an equivalent safety profile.