19-Noraldosterone, recently shown to be produced in the human adrenal gland, possesses potent mineralocorticoid and hypertensinogenic activity. A possible precursor, 18,19-dihydroxycorticosterone, has been identified in human urine, with both steroids acutely regulated by the renin-angiotensin system. The secretion of aldosterone declines with advancing age. To elucidate the effect of aging on the urinary excretion of 19-noraldosterone and 18,19-dihydroxycorticosterone, we measured their urinary concentrations in 51 normotensive subjects aged 20-70 years. We observed significant negative correlations between age and the urinary excretion of 19-noraldosterone and 18,19-dihydroxycorticosterone (r = -0.69, r = -0.65, P < 0.05, respectively). Urinary and plasma aldosterone and PRA similarly decreased with aging. These results suggest that 19-noraldosterone may be chronically regulated in part by the renin-angiotensin system.