Several diseases can be transmitted to infants via transfusion. The risk of acquiring an infection via transfusion is greatly increased in sick premature infants because they receive frequent transfusions. The full-term infant is not fully competent immunologically, and the premature infant is even less able to deal with infection. Ideally, the transfusion of infected blood, especially into immunoincompetent recipients, should not occur. However, because screening for malaria in nonendemic regions is not practical, physicians caring for sick premature babies should consider transfusion-acquired malaria as a possible cause of illness, especially when there is no response to antibacterial therapy.