Polycystic ovary syndrome (PCOS) is a common disorder which affects about 10% of women in reproductive age. According to the Rotterdam consensus criteria, PCOS is diagnosed in the presence of two out of three following symptoms: (1) oligomenorrhoea, anovulation, (2) hyperandrogenism, (3) polycystic ovaries at ultrasound scan. Etiology of the syndrome, although widely speculated, still remains unknown. Analysis of the prevalence of PCOS among the families reveals that genetic contribution to the outcome of the syndrome is highly probable. However, the pattern of inheritance is not clear. On the basis of common clinical symptoms, disorders in metabolic pathways involved in biosynthesis and action of steroid hormones and insulin, as well as in development of inflammatory state, have been searched. As part of the research, large-scale analysis of “candidate genes”, whose protein products are engaged in several metabolic processes, have been performed. According to research, at least in some of them mutations or polymorphisms, mainly SNP-type, affecting transcription of the gene or protein properties, have been found. Nevertheless, none of them seem to play a key role in the pathogenesis of the syndrome, indicating that PCOS may be a result of several genes abnormalities interactions. In this review we present the current state of knowledge concerning particular genes, products of which seem to take part in the modulation of the clinical sings of the disease.