The progression of renal failure has been suggested to be altered by dietary manipulation of protein based on the presumption that the progressive nature of CRF may be caused by the vicious cycle driven by some toxic metabolite uncleared by failing kidney. We studied 29 female Sprague-Dawley rats aged 12 weeks weighing 226 to 290 gm subjected to a 5/6 nephrectomy. 2 days after, group C (16 rats) were given a commercially prepared diet (CE-2, Japan Kurea). While group A (13 rats) were given the same diet and 5% AST-120. Initial serum creatinine of both group was 2.2 mg/dl. After 9 weeks, all surviving rats were sacrificed for evaluation of renal histology. During the observation period, survival rate, Ccr, urinary creatinine and urea excretion were significantly better in group A rats. Result also showed a better weight increase with concomitant increase in protein catabolic rate in group A rats. These result showed the beneficial effect of AST-120 in uremic rats in terms of survival rate and delaying the progression of CRF despite the presence of increased protein catabolic rate. Based on this study, one way of preventing the progression of renal failure is through removal of some toxic metabolite in the gastrointestinal tract by the use of oral adsorbent as exemplified by AST-120.