A 68 year old woman presented a rapidly progressive renal failure associated with manifestation of a systemic disease and showed, at renal biopsy, a picture of severe necrotizing angiitis with a proliferative glomerulonephritis with 80% crescents. Renal function improved after a treatment with high doses of steroids, heparin and immunosuppressive drugs. Immunofluorescence study showed diffuse predominant deposits of IgA and C3 both along capillary walls and in the majority of vessels. Skin and muscle biopsies failed to show lesions of vasculitis. The nosological definition of this condition is discussed, the patient presenting with some aspects suggestive of a Schönlein-Henoch syndrome, and others of polyarteritis nodosa.