The polycystic ovary syndrome (POS) is a common hormonal disorder in women all over the world; it is characterized not only by reproductive disturbances but by endocrine and metabolic as well. Women with POS are subjected to an increased risk for the development of type 2 diabetes mellitus, metabolic syndrome and sterility. This article presents information on POS problems, its history. The main etiological factors predisposing to the development of polycystic ovaries syndrome are highlighted. Besides, actual data on pathogenetic theories of POS development are presented.