The indices of three adrenal cortex functions were investigated in 517 patients with a moderately severe and severe forms of diabetes mellitus of various duration, outside of the ketoacidosis and hypoglucemia states. Both during decompensation and at the period of unstable compensation (subcompensation) of the disease 3--60% of the patients displayed increased indices of glucocorticoid and mineralocorticoid functions, and 20--38%--of the androgenic ones. Along with different frequency of detection, there was revealed a distinct non-uniformity of different indices elevation. A prevalence of the mineralocorticoid function activation was noted. As suggested, at the mentioned periods of diabetes mellitus functional activity of the adrenal cortex reflected various phases of the oscillatory adaptation process to the frequently repeated stress actions (metabolic disturbances). Possible causes of prevalent aldosterone excretion elevation are discussed.