A description of the clinical observation of the child at the late stage of Kawasaki disease is presented. In our observation, an aneurysm of the circumflex branch of the left coronary artery was discovered on the echocardiography of the child. MRI results of the brain with vascular program revealed a picture of vasculitis, fusiform expansion of the A1 segment of the right anterior cerebral artery, M1 segment of the left middle cerebral artery. Systemic vasculitis was diagnosed at the late stage of disease. This case shows the importance of better awareness of pediatricians, cardiologists, neurologists about Kawasaki disease, its manifestations at the early stage and possible long-term complications, as well as modern approaches to treatment.