Symptoms from the genitourinary system are unusual in Kawasaki disease (KD). Renal involvement is even rarer and it is confirmed by biopsy when the person is alive. We describe the case of an 11-year-old boy admitted to the hospital complaining about prolonged fever (5 days) and hematuria. His urinalysis showed also pyuria, proteinuria and urinary renal tubular epithelial cells concentrations. During the next days, the patient presented limb edema. After almost 2 weeks of hospitalization the patient was transferred to the intensive care unit because of melena and intense abdominal pain. Upon admission, the patient collapsed and died. The diagnosis of KD was established during autopsy. The macroscopical and histopathological examination of the heart showed increased dimensions and weight and multiple thrombi in the coronary arteries with intramural dense polymorphonuclear inflammatory infiltration and necrosis. Histological examination of the kidneys revealed normal glomerulus, mild expansion of mesangial matrix, interstitial infiltration with lymphocytes, plasmatocytes and eosinophiles, normal vessels and normal immunofluorescence.