Ischemic cardiomyopathy in childhood is related with congenital and acquired pathologies which could lead to serious cardiac sequelae as myocardial infarction and sudden death. Unfortunately, when coronary artery malformations are excluded, it is difficult in some cases to be completely certain on the etiology of the arterial coronary disease, due the lack of pathognomonic diagnostic tests. Case report of 6 year old child, with severe coronary artery disease: aneurysm of main branch of left coronary artery; left anterior descending branch and right coronary artery occlusions with accentuated myocardial dysfunction. We believe that the diagnosis of Kawasaki disease is presumptive in this patient. The principal aspects to elucidate the etiology of coronary artery disease are analysed, as well as the importance of identifying patients without known previous illness, but with severe coronary artery lesions, as in this reported case.