The authors studied the concentration of pregnancy-associated alpha2-glycoprotein (PA alpha2GP), a sensitive marker of estrogen-dependent tumors, and the association of its level with the serum content of a number of hormones: follicle-stimulating hormone, luteinizing hormone, estradiol (E-2), dehydroepiandrosterone sulfate (DEAS-S), and testosterone in females receiving the groups of drugs containing: 1) estradiol valerate; 2) 17beta-estradiol, and 3) tibolone. The type of the active ingredient of a drug and the duration of its administration were shown to differently affect both the concentration of hypothalamopituitary hormones and steroid sex hormones and the level of PA alpha2GP). The latter increased significantly in Group 1 and insignificantly in Group 2 and did not differ from the normal values in Group 3, at the same time the concentration of E-2 elevated in Groups 1 and 2, rather than in Group 3; the level of DEAS-S increased in Groups 2 and 3 irrespective of the duration of use. Moreover, there were elevated levels of testosterone in Group 3 and those of DEAS-S in Group 1 only when the drugs were administered for 3-6 months. A number of correlations were found in the levels of PA alpha2GP with those of steroid hormones. The authors consider that individual monitoring of the level of PA alpha2GP in the females who need hormonal therapy in menopause provides a useful guide to choosing a drug, monitoring its use efficiency, and preventing malignant proliferation in proper time.