In view of the problem of transfusional malaria, the prevalence of malaria parasitaemia in transfused donor blood was assessed. Blood film examination for malaria parasites on Giemsa-stained donor blood which was used for transfusion to neonates in Benin City, Nigeria was carried out over a 6-month period. Blood group O was the dominant blood type (17%). A high malarial parasite prevalence rate of 40% was noted in the transfused donor blood and Plasmodium falciparum was the dominant infecting species. All blood groups and rhesus factor types were infected with malarial parasites. There was no significantly increased malarial infection rate in any particular blood group type. The neonate, who is known to be immunologically naive, is at high risk of symptomatic malaria acquired through blood transfusion. All neonates who require blood transfusion should be given chloroquine sulphate soon after transfusion, at a dose of 5 mg/kg/day for 3 days, when the parasites are chloroquine-sensitive. In cases of chloroquine resistance, quinine sulphate or halofantrine hydrochloride is an acceptable alternative. Where feasible, donor blood screening for malaria should be carried out before transfusion to any neonate.