This multicentric double-blind, dose-ranging study was to compare efficacy and safety of two oral doses of granisetron solution in the prevention of chemotherapy-induced emesis in children with malignant diseases : 294 children, aged 1 to 16, treated with a moderately or highly emetogenic chemotherapy were randomly assigned to receive oral granisetron either 20 microg/kg (n = 143) or 40 microg/kg (n = 151) before and 6 to 12 hours after the start of chemotherapy. Fifty-one percent of patients treated with 20 microg/kg bd of oral granisetron solution achieved a complete response (no vomiting, no worse than mild nausea, no rescue therapy and no withdrawal during the specified period) and 59% achieved a major response (no more than one episode of vomiting, no worse than mild nausea, no rescue therapy and no withdrawal during the specified period). There was no difference between the two oral doses of granisetron. Treatment was rated as good or very good by investigators in 70% of cases. In conclusion, oral granisetron suspension either at 20 microg/kg bd or at 40 microg/kg bd showed good efficacy and safety in the prevention of chemotherapy-induced emesis in children with malignant diseases. Oral granisetron solution can be used as prophylaxis of emesis in children receiving moderately or highly emetogenic chemotherapy.