The long-term consequences of the cardiovascular sequelae in Kawasaki disease remain uncertain. We identified 594 consecutive children with acute Kawasaki disease between 1973 and 1983, and this cohort was followed up for 10 to 21 years (mean, 13.6 years). In all patients, we evaluated coronary lesions by coronary angiography just after the acute stage. One hundred and forty-six patients (24.6%) were diagnosed as having coronary aneurysms. A second angiogram was performed 1 to 2 years later in all 146 patients who previously had coronary aneurysms, which demonstrated that 72 (49.3%) of these 146 had regression in the coronary aneurysm. A third angiogram was performed for 62 patients, a fourth for 29, and a fifth for 17. By 10 to 21 years after the onset of the illness, stenosis in the coronary aneurysm had developed in 28 patients. Myocardial infarction occurred in 11 patients, 5 of whom died. In the 26 patients with giant coronary aneurysms, stenotic lesions developed in 12, and no regression occurred. The 448 patients with normal findings at the first angiogram subsequently never developed any abnormal cardiac findings. Systemic artery aneurysms developed in 13 patients (2.2%), and valvular heart disease appeared in 7 (1.2%). The incidence of coronary aneurysm in acute Kawasaki disease was 25%, 55% of which showed regression. During follow-up, ischemic heart disease developed in 4.7% and myocardial infarction in 1.9%. Death occurred in 0.8%.