Kawasaki disease is a febrile vasculitis affecting young children, which may lead to coronary aneurysms. Echocardiography, although sensitive in detecting coronary aneurysms, has a limited role in diagnosing coronary thrombus. Here we report the case of a 10-year-old boy who presented with typical features of Kawasaki disease with giant coronary aneurysms. His follow-up echocardiogram revealed coronary arterial thrombus.