Serum quinine concentrations were measured in seven children after intravenous infusion of quinine dihydrochloride, in eight children after intramuscular injection of quinine dihydrochloride, and in six children after nasogastric administration of a solution of quinine dihydrochloride. The mean (+/- SD) half-life of quinine was 11.1 +/- 4.8 hours, and the volume of distribution was 1.39 +/- 0.37 L/kg. To attain a serum level of 10 microgram/ml quinine, we suggest that children with severe malaria be given a loading dose of 20 mg/kg quinine dihydrochloride parenterally, followed by 7.5 mg/kg every 8 hours. Once recovery begins, quinine sulphate 10 mg/kg may be given orally every 8 hours. Serum concentrations should be monitored, if possible, because they vary greatly from person to person. Quinine is rapidly and completely absorbed after either intramuscular or nasogastric administration.