Out of 152 cases of Acute renal failure (ARF) 32 patients (21%) were subjected to kidney biopsy. All patients had intrinsic ARF. Prerenal azotemia and obstructive uropathy were excluded. Histologic observations were: Crescentric glomerulonephritis in 7 (21.9%), acute endocapillary proliferative glomerulonephritis 5 (15.6%), acute interstitial nephritis 7 (21.9%), necrotizing vasculitis 4 (12.5%), acute tubular necrosis in 5 (15.6%) and membrano-proliferative GN with superimposed crescent in 2 (6.2%) while renal cortical necrosis was seen in 6.2% of cases. Prebiopsy diagnosis was correct in only 10 (31.25%) cases. The result of biopsy had altered clinical diagnosis in 22 (68.75%) patients and precise renal biopsy diagnosis resulted in therapeutic changes in 54.8% of patients with ARF.