The author investigated during the past 17 years 595 patients with iatrogenic damage of bone mineralization, incl. 302 patients where the disorder developed after drugs and 293 where osteopenia developed after surgery. In demineralizations after the use of drugs in the first place corticoids participate, to a smaller extent non-thiazide diuretics and antiepileptic drugs. The largest ratio of operations causing demineralization is formed by ovariectomies, in particular if performed before the menopause, followed by gastric surgery, operations of the gallbladder, small intestine and strumectomy. Finally the author emphasizes the necessity to know iatrogenic bone damage, its early diagnosis and prevention.