Four cases of acute renal failure induced by intravenous immunoglobulin are presented, and the literature on the subject is reviewed. The clinical course varies from asymptomatic serum creatinine elevation to anuric renal failure occurring within days of the institution of therapy, followed by the rapid recovery of renal function after termination of therapy. The renal histology demonstrates severe tubular vacuolization with cellular swelling and preservation of the brush border. Glomerular endothelial, mesangial, and epithelial cells also may demonstrate swelling and vacuolization. There is no evidence for inflammatory or immune complex-mediated etiologies. The immunoglobulins or carbohydrate additives in the preparations appear to have a unique and reversible effect on the glomerular and tubular cell function.