Kawasaki disease (KD, or acute febrile mucocutaneous lymph node syndrome (MCLS)) was first described as a clinical entity in 1967 by Dr. Tomisaku Kawasaki of the Japan Red Cross Medical Center. Originally, it was thought to have a favorable prognosis, but as epidemiological surveys, augmented by pathological studies, have shown, it has come to be recognized as an often fatal disorder. In this report, the clinical symptoms, historical background, present status of research and epidemiological problems of KD are first described, and then we present a pathological and morphological outline of KD, focusing on pathological changes in the blood vessels, and the relationships of these changes to 1) the morphogenesis of arteritis, 2) the mechanism of coronary artery aneurysm formation and its sequelae, and 3) juvenile arteriosclerosis.