Three children are described in whom pre-transfusion samples were HIV-seronegative and post-transfusional samples, obtained within 1 week after transfusion, were HIV-seropositive. Two of them developed a transient fever within 1 week of receiving the blood transfusion, and a transient generalized skin eruption which lasted for about 2 weeks. All three developed persistent generalized lymphadenopathy. One child developed a lumbar herpes zoster 7 months after transfusion. IgM Western blots demonstrated the presence of antibodies to protein bands p17, p24 and p55 in all three children. These three case reports suggest that children who receive a seropositive blood transfusion are at high risk for developing acute manifestations of HIV infection.