Since the original report of Kawasaki disease in 1967 more than 150,000 cases have been reported in Japan. Although there have been no nationwide epidemics in Japan since 1987, more than 6,000 newly diagnosed cases are reported every year, and the number has been increasing year by year despite the decreasing birth rate. The etiology of the disease is still unknown. High dose intravenous gammaglobulin is currently used during the acute phase in 84% of the patients in Japan with a concomitant decrease in coronary arterial sequelae. However, 7-13% of the patients still have persistent coronary artery aneurysms after the acute stage. The aneurysms are seen mostly in the proximal coronary arteries, and are often associated with aneurysms in the distal coronary artery segments (Figure 1A, 2A). Most of the patients show a decrease in the size of aneurysms soon after the acute phase (Figure 1B). However, the aneurysms may progress to obstructive lesions even after initial regression (Figures 1C, D, 2B). Such obstructive lesions may cause sudden death or myocardial infarction. Long term follow-up of coronary artery lesions has revealed several characteristic features, including progressive localized stenosis (Figure 1D), extensive recanalizations (Figure 2D) and development of collateral arteries. Progressive increases in aneurysm size and the appearance of new aneurysms in the late phase have also been reported. The basic mechanisms of the coronary arterial remodeling in Kawasaki disease have not yet been elucidated. Only recently has immunohistochemical staining in formalin-fixed specimens become feasible. This is a major technical breakthrough since it is almost impossible to obtain fresh frozen specimens of coronary artery lesions of Kawasaki discase. In this paper, we compare immunohistochemical findings in coronary artery lesions with the corresponding coronary angiographic findings, and attempt to make inferences as to the mechanism of remodeling both in early and late phases of the disease based on the expression of vascular growth factors.