The effectiveness of ramosetron tablets and granisetron injection was compared for reducing the frequency of nausea, vomiting, and anorexia in patients with malignant glioma undergoing ACNU chemotherapy. Patients with malignant glioma to be treated with ACNU chemotherapy were randomly assigned to receive oral ramosetron (20 patients) or intravenous granisetron (19 patients) prior to ACNU injection. Gastrointestinal toxicity within 48 hours of ACNU injection was compared to that in patients who had received ACNU chemotherapy with dopamine D2 receptor-blocker as a historical control group. Within 24 hours of the administration of ACNU, 15 of the 20 patients treated with ramosetron and 16 of the 19 treated with granisetron were nausea-free, and 14 of the former and 14 of the latter regained their normal appetite. There was no significant difference in the anti-emetic effects. Ten of the 17 controls experienced no vomiting within 6 hours of the injection of ACNU, five were nausea-free within 24 hours, and two retained their normal appetite within 24 hours. Oral ramosetron has the same anti-anorectic and anti-emetic effects as intravenous granisetron. Ramosetron tablets are less expensive and are easy to take, so should be on the list of first-choice anti-emetic drugs for patients treated with ACNU chemotherapy.