To study the histopathology of the myocardium in Kawasaki Disease (KD) with various coronary angiographic fmdings, right endomyocardial biopsy specimens were evaluated on 20 boys and 16 girls with this disorder. KD with coronary artery lesions (CAL) showed various histopathological abnormalities, such as myocellular hypertrophy in 44%, degeneration in 61%, interstitial fibrosis in 44% and endomyocardial changes in 22%. KD without CAL revealed myocellular hypertrophy in 44%, degeneration in 50%, disarray in 28% and interstitial fibrosis in 6%. As in patients with long‐standing KD, more than three years after onset, myocardial changes such as myocellular hypertrophy, disarray and interstitial fibrosis persisted, it is suggested that cardiomyopathy may develop in some patients with KD.