A three months old girl was admitted to the hospital for evaluation of pallor and abdominal distension. There was anemia, thrombocytopenia and extramedullary hematopoiesis. In the long bone roentgenogram medullary areas could not be distinguished and bone densities were increased. The patient was diagnosed for osteopetrosis with these findings and prednisolone treatment was begun and then discontinued since it was not effective. In the follow up, the need for blood transfusions decreased and then disappeared. We present a case which was diagnosed as osteopetrosis and followed up by blood transfusions and of which hematologic findings improved with age.