The present study was conducted to provide morphological evidence for allopurinol-induced nephrotoxicity in rats and its prevention by the antioxidant butylated hydroxytoluene (BHT). The kidneys of male Sprague Dawley rats fed a diet containing 0.3% allopurinol for 25 days exhibited a marked increase in the weight (2.5 times) as compared to the controls (without allopurinol). Upon microscopic examination, extensive tubulo-interstitial injury leading to structural damage was observed. Feeding BHT (0.4%) along with 0.3% allopurinol brought about a remarkable amelioration of the nephrotoxicity. The results indicate that usage of BHT along with the antiurecemic drug, allopurinol, may be helpful in improving the allopurinol-induced nephrotoxicity observed in some gout patients.