Increased plasma aldosterone concentrations (PACs) are associated with higher cardiovascular risk and target organ damage (TOD). Hyperglycemia can potentiate the cellular effects of aldosterone, and the prevalence of diabetes in primary aldosteronism (PA) is 7%-59%. The prevalence of PA in hypertensive individuals is estimated to be 10%-14%. This study of 61 hypertensive diabetic patients not taking spironolactone and with serum creatinine values <2.5 mg/dL sought to establish the prevalence of PA in hypertensive diabetics and compare the prevalence of PA in patients with TOD with those patients without TOD. PA was suspected if PACs were >15 ng/dL and plasma renin activity was <1 ng/dL/h (ratio >30). Although 14 patients had suppressed renin with PACs >8 ng/dL (including two with PACs >11 ng/dL), none met our criteria for PA. There was no correlation between PAC and TOD. This study indicates that routine screening for PA in hypertensive diabetic patients is not justified and that PAC does not correlate with TOD. Further study is needed.