Forty-four patients (11 men and 33 women) with primary chronic adrenal insufficiency (CAI) treated by substitute synthetic glucocorticoids (GC) prednisolone and dexamethasone and 9a-fluorohydrocortisone (cortineff) were examined in order to investigate the effects of various factors on changes in mineral compactness of bone tissue (MCB). In men the disease duration was 10.33±1.4 years, in women 11.64±3.49 years. Twenty (60%) women were postmenopausal, ten of these (50%) for more than ten years. None of these women was treated by estrogens. Bi-energy x-ray absorptiometry (BRA) of forearm bones was carried out in all 44 patients and quantitative computer-aided tomography (CAT) of L2, L3, and L4 vertebrae was carried out in 25 patients. Plasma levels of dihydroepiandrosterone sulfates (DEA-S) were measured; in men plasma testosterone was measured. A decrease of MCB to less than —1 SD by the T index was detected by BRA in 72.7±13.4 men and in only 42.4±8.6%o women, and by the Z index in 45.5±15.01 men and 33.3±8.2% women. CAT of the spine showed MCB decrease by the T index in 83.3±15.23% men and 63.15±11.07%o women and by the Z index in 16.7±15.23%o men and 26.3±10.1 women. Despite an appreciably high incidence of osteopenia and osteoporosis in men, the difference between men and women by these parameters is insignificant. Among women at least 80% osteopenias and osteoporosis occurred in postmenopausal women. In women with decreased MCB (Z<—1) the duration of the postmenopause was significantly (p<0.05) higher than in women with normal MCB. No significant differences in the disease duration, patients’ age, and plasma levels of DEA-S and testosterone between groups with normal and decreased MCB were observed in both men and women. Analysis of correlations of the results of both osteodensitometry methods showed a strong inverse correlation between MCB and duration of postmenopause. In four men CAT of the spine revealed a strong positive correlation between MCB and testosterone level. Hence, a characteristic feature of the osteopenic syndrome in patients with CAI treated by substitute synthetic GC is its increased incidence in men, compatible to that in women; the duration of postmenopause is a significant factor of risk of osteopenia in women with CAI.