The aim of the study was to analyse two cases of Kawasaki disease--the first one with myocardial infarction and the second with positive outcome. Kawasaki disease is a fever disease usually occurring in very young children. Vasculitis is a characteristic feature of Kawasaki disease. Etiology of this disease is unknown. Diagnosis is based on typical clinical symptoms such as: fever, rash, conjunctivitis, lymphadenitis colli, inflammation of the mucous membranes, erythema of the hands and feet. The treatment can prevent thrombosis, myocardial infarction which are the most serious complications of the disease. Kawasaki disease is treated with intravenous gamma--globulin therapy and high dosage acetylsalicylic acid at the beginning of the disease. Such a treatment of Kawasaki disease prevents the coronary vessel lesions.