We describe a patient with gross hematuria, severe renal failure and symptoms suggestive of systemic vasculitis. Renal biopsy showed very focal and segmental necrotizing glomerulonephritis without crescents. A few C3 deposits were seen by immunofluorescence. The tubular lesions, on the contrary, were very severe, consisting of tubular cell necrosis and ruptured tubular basement membrane, associated with large numbers of intraluminal erythrocytes and erythrocytic casts. After gross hematuria had cleared, renal function slowly recoverd. Because of biopsy findings and clinical course, acute renal failure in this patient was considered to be due to the tubular lesions caused by gross hematuria.