Severe visceral involvement in leukocytoclastic vasculitis is rare. We report here the case of a 2-month-old male infant with leukocytoclastic vasculitis who initially presented with fever and skin purpura. Endomyocarditis with mitral valve regurgitation, multiple hepatic infarction, and pulmonary hemorrhage developed later. The patient was successfully managed with an aggressive treatment of high frequency oscillation ventilation and extracorporeal membrane oxygenation together with corticosteroid and azathioprine therapy for 3 months. Valvuloplasty was also performed due to irreversible damage of the mitral valve, although long-term oral anticongestive medications were also needed.