The pathogenesis of acute renal failure may involve, among other causes, ischemia, vascular congestion, arachidonic acid pathways, and reactive oxygen metabolites. The aim of this study is to evaluate the effects of pentoxifylline and vitamin E on the prevention of experimental acute renal failure induced by glycerol. Eighty-five Sprague-Dawley rats weighing 170–230 g were included in the study. The rats were randomly divided into four groups: group 1 was given 1 ml saline; group 2, glycerol; group 3, glycerol plus vitamin E, and group 4, glycerol plus pentoxifylline. Extent of histological renal tubular necrosis and regeneration in each animal were graded. Blood urea nitrogen, serum creatinine, and creatine kinase concentrations were measured. Mean blood urea nitrogen and serum creatinine concentrations and tubular injury scores were significantly lower in group 1 than in groups 2–4 (p < 0.001), but there were no significant differences among groups 2–4. We conclude that postinsult administration of vitamin E and pentoxifylline does not have a beneficial effect on prevention and severity of acute renal failure and that controlled, multicenter studies involving a large number of patients are needed to clarify this subject.