A 34-year-old man was admitted to Prier hospital because of head and right foot injuries caused by a traffic accident. Two months after admission, he complained of abdominal pain and bloody stool. Shortly after purpura appeared on both legs. He received an exploratory laparotomy and showed multiple jejunal ulcer. A pathological examination of the jejunum revealed necrotizing vasculitis of the small arteries. After the operation, he had arthralgia and the laboratory examination showed massive urinary protein. Arthralgia, abdominal pain and bloody stool disappeared with the administration of 100 mg per day of prednisolone (PSL), but nephrotic syndrome was not relieved. As a result he was referred to our hospital. And after admission, PSL was gradually tapered to 60 mg per day. Then an open renal biopsy was performed, and pathological examinations revealed focal proliferative glomerulonephritis in which 31% of the glomerulus showed fibro-cellular crescents. A direct immunofluorescence of the renal biopsy showed mesangial deposits of IgA, IgG, C3. The patient was treated with anti-coagulant therapy and PSL. Urinary protein was gradually decreased to 0.7 g/day, and his creatinine clearance was 23 ml/min five months after the renal biopsy. In this case, although the renal biopsy specimens and clinical symptoms were compatible with HSP, a pathological examination of jejunum revealed vasculitis of the small arteries. In literature, HSP is a syndrome characterized by vasculitis of arterioles, capillaries and venules. As a results of those findings, we think the diagnosis of this patient is PN with mesangial IgA depositions of renal glomeruli.