During the early stages of Kawasaki disease, a marked increase in oxygen-free-radicals (OFRs), which are produced by activated polymorphonuclear cells, may induce coronary arteritis. Early use of high-dose intravenous gamma-globulin (IVIG) and aspirin effectively blocked this deteriorating course of coronary arteritis; however, late use of IVIG, even using a high-dose schedule, did not achieve the same efficacy. The causes and reactions to the scenario of IVIG refractoriness have rarely been mentioned in the literature. We present an 11-month-old male infant with Kawasaki disease and deteriorating coronary arteritis owing to late use of IVIG who showed dramatic responsiveness to the addition of alpha-tocopherol and ascorbic acid. We also discuss the possible mechanism.