Two elderly patients with mineralocorticoid excess state due to 11 beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) impairment are described. Moreover, the role of the precursor-product ratios of the steroids reflecting 11beta-HSD2 activity was estimated in 5 patients, including 3 patients reported previously by us. Significant elevations of urinary cortisol/cortisone ratios were observed, whereas urinary tetrahydrocortisol (THF)+allo-THF/tetrahydrocortisone (THE) ratios were not elevated significantly. Furthermore, an even more distinct elevation of serum cortisol/cortisone ratio was evident in all instances of 5 patients, suggesting a significant clinical role of the serum cortisol/cortisone ratio in the diagnosis of 11beta-HSD2 impairment.