Giant hemangiomas are rare in newborn babies and may cause some life-threatening complications such as congestive heart failure and coagulopathies including severe thrombocytopenia, microangiopathic hemolytic anemia and bleeding such as Kasabach-Merritt syndrome. We have presented here one infant case with a right lower brachial plexus paralysis due to giant hemangioma treated successfully with interferon alpha and have discussed the treatment. This is the first case of Kasabach-Merritt syndrome associated with a right lower brachial plexus paralysis treated with interferon in the literature to our knowledge. The administration of interferon-alpha might be indicated as a therapy for severe, life-threatening and giant hemangiomas such as Kasabach-Merritt syndrome, especially when there is resistance to steroid. However, more extensive data and new patients are needed to clarify this issue.