Thyroid hormones play the essential role in the regulation of metabolism and bone remodeling in physiological conditions and in the course of thyroid dysfunction. Introduction of densitometry to the diagnostics of osteoporosis has made possible the evaluation of influence of both hyperthyroidism and hypothyroidism and their treatment on bone mineral density. Moreover it became possible to estimate the influence of treatment with exogenous thyroid hormones on the skeletal system. Authors presented mechanisms of the thyroid hormones action on bone tissue and analysed current state of knowledge concerning the influence of the thyroxine treatment with replacement and suppressive doses on the bone mineral density. The influence of thyroid hormones on the skeletal system with respect to premenopausal and postmenopausal period was also discussed. Great discrepancies in literature data and its reasons were underlined.