A 2-month-old girl presented with enlarged head girth, generalized petechiae, anemia, coagulopathy and hepatosplenomegaly. Imaging studies showed a huge, dumbbell-shaped intracranial hemangioma located between the falx, and involving the supra- and infra-tentorium, extending through the posterior fontanel to involve the subgaleal area. A urine culture grew cytomegalovirus. Severe thrombocytopenia was refractory to a massive platelet transfusion, intravenous immunoglobulin and corticosteroid therapy. Hypertension, pulmonary hemorrhage and sepsis complicated the course. After establishing a diagnosis of Kasabach-Merritt syndrome, subcutaneous injections of alpha-interferon were given with an initial dose of 1 x 10(6) IU/m2 followed by 3 x 10(6) IU/m2 per day for 12.5 mo. Her platelet count rose gradually and became stable after 1.5 mo of interferon treatment. The intracranial hemangioma regressed remarkably and the hepatosplenomegaly was also resolved. The infant showed good growth and development, without obvious side-effects during the 23-month follow-up period. The treatment with recombinant alpha-interferon appeared to be effective in reversing thrombocytopenia associated with the patient's massive intracranial hemangioma.