Immunohistological analysis of 1146 renal biopsies revealed IgA associated glomerulonephritis (IgAGN) in 83 (7.24%) patients (33 children, 50 adults). Clinical features were unusually severe in a high proportion. Nephrotic syndrome (NS) responding poorly to prednisolone was found in 24%, hypertension (HT) in 39%, and azotemia in 34% of patients. NS was slightly more frequent in children than in adults, but HT and azotemia occurred twice as often in adults as in children. Histologically, extensive glomerular crescents and sclerosis were prominent. In addition, moderate arteriolitis and arteriolosclerosis and marked tubulointerstitial nephropathy were notable features. Thus, a low incidence and marked severity characterized IgAGN in this study.