IgA-glomerulonephritis (IgA-GN) accounts for approximately 20 per cent of all glomerulonephritis in our unit. Seventeen out of 50 patients with IgA-GN developed renal failure, which appeared in 11 out of 17 over the course of a mean follow-up of 68 months. Haemodialysis was required in three patients. Twenty-two out of 50 patients had hypertension, five with malignant hypertension. Perivascular IgA deposits were found in skin biopsies of 29 per cent of patients with IgA-GN and also in 19 per cent of patients with other GN, but not in healthy controls. Mucosal (salivary and nasal) secretory IgA concentrations were normal. In cutaneous and glomerular IgA/IgM deposits, IgA1 was demonstrated using monoclonal antibodies. No excess of HLA-A, B or DR antigens and no relation of clinical course and HLA-Bw35 were found.