Kasabach-Merritt Syndrome (KMS) originally referred to a hemangioma associated with life-threatening thrombocytopenia and a consumption coagulopathy. Treatment includes surgery, steroids, and alpha interferon. However response may be unsatisfactory and mortality rates of 10-37% have been reported. We report a case of a 4-month-old male whose disease had not responded to steroids and alpha interferon. He required ventilation, and his condition was deteriorating. It was thought that he would probably die of his condition. He was treated with 9 Gy in three fractions weekly of radiotherapy (RT). Clinical response was good and he is well and free from progression 4 years and 7 months after RT. A review of the literature on the role of RT in the management of hemangiomas is presented.