Raised serum uric acid levels are associated with increased cardiovascular risk in many patient groups, including those with chronic kidney disease. Mineralocorticoid receptor antagonists are showing great promise as a means of lowering cardiovascular risk in patients with chronic kidney disease; yet their actions on serum uric acid are not known. The present study examined the actions of the mineralocorticoid receptor antagonist spironolactone on serum uric acid in patients with early chronic kidney disease.