Hyperuricemia is associated strongly with the development of hypertension, renal disease, and progression. Allopurinol decreases serum uric acid levels by inhibiting the enzyme xanthine oxidase. We hypothesized that administrating allopurinol to decrease serum uric acid levels to the normal range in hyperuricemic patients with chronic kidney disease may be of benefit in decreasing blood pressure and slowing the rate of renal disease progression in these patients.