Microscopic polyangiitis is a systemic small-vessel vasculitis, which may involve multiple organs, but cardiac involvement is relatively rare. We report a case of microscopic polyangiitis with multiple organ involvement, in which myocardial infarction was the early manifestation of the disease. A 53-year-old man presented with sudden papulovesicular eruptions and swellings on the face, posterior neck, dorsa of both hands and fingers, and with diffuse erythematous patches on the back. He had suffered from renal dysfunction, arthralgia, and hypertension for more than 8 years. He had been admitted to the department of cardiology for acute myocardial infarction and had suffered from recurrent gastrointestinal bleeding, renal failure, acute pancreatitis and sepsis during the admission. Histopathologically, small-vessel leukocytoclastic vasculitis with out granuloma was seen. Direct immunofluorescence showed no immune deposite. A high serum level of P-ANCA was detected by ELISA.