Women with polycystic ovary syndrome (PCOS) seem to have impaired reproductive performances. It is generally considered that an altered ovulatory function is the main cause of infertility in the affected women. However, other factors may play a role in the pathogenesis of the PCOS-related infertility. During the last years, more and more importance has been given to endometrium as contributor of the PCOS-related subfertility. In the present narrative review, the main and recent experimental and clinical data will discuss in order to clarify the role played by the endometrium in the PCOS-related subfertility. The overall analysis of available data suggests that, in women with PCOS, the endometrium is primarily affected, and closely and deeply influenced by the several hormonal, metabolic, clinical alterations related to the syndrome.