Purpose : To evaluate the coronary angiographic findings of patients with Kawasaki disease and to investigatethe natural course of aneurysms of the coronary artery. Materials and Methods : Between June 1989 and January1996, we evaluated the coronary angiographic findings of 12 consecutive children with Kawasaki disease whosecoronary artery was abnormal. On initial study, we retrospectively analysed the size, configuration, and locationof 35 coronary aneurysms, and in five children, follow-up coronary angiography was performed at intervals of 17 to28 (mean, 23) months. Seventeen aneurysms detected on initial study were evaluated for subsequent change. Results: Initial coronary angiography showed the aneurysms to be diffuse in 7 cases(20%), saccular in 7(20%), fusiform in17(49%), and tubular in 4(11%). They were large in 10 cases (29%), medium in 22(63%), and small in 3(9%) ; theirlocation in the coronary artery was proximal(71%), middle in 6(17%), and distal in 4(11%). The right coronaryartery was involved in 18 case(51%), and the left coronary artery in 17(49%). Follow-up study showed that theaneurysm had regressed in 11 cases (65%), persisted in 2(12%), and progressed to stenosis in 1(6%) and occlusionin 3(18%). Two(50%) of the four large aneurysms showed complete occlusion. On the other hand, medium and smallaneurysms showed regression in 9(82%) and in all cases, respectively. Diffuse-type aneurysms were complicated byocclusion in 2 cases (50%) and stenosis in 1(25%). On the other hand, six fusiform aneurysms (75%) and allsaccular and tubular aneurysms had regressed. Conclusion : In patients with kawasaki disease, informationregarding the size and configuration of coronary aneurysms may be useful for predicting the natural course andprognosis of coronary artery disease.