The endocrinologic and metabolic abnormalities of women with polycystic ovary syndrome (PCOS) can result in a series of endometrial diseases. Abnormalities of hyperandrogenism and hyperinsulinemia that may be found in PCOS can elevate the levels of E 2 indirectly, reduce progesterone secretion and induce some growth factors such as vascular endothelial growth factor (VEGF) and insulin-like growth factors (IGFs) over expression, which may have a major impact on endometriosis occurrence and development. We suppose that there is a possible connection between PCOS and endometriosis. The endocrinologic and metabolic abnormalities of women with polycystic ovary syndrome (PCOS) can result in a series of endometrial diseases. Abnormalities of hyperandrogenism and hyperinsulinemia that may be found in PCOS can elevate the levels of E 2 indirectly, reduce progesterone secretion and induce some growth Factors such as vascular endothelial growth factor (VEGF) and insulin-like growth factors (IGFs) over expression, which may have a major impact on endometriosis occurrence and development. We suppose that there is a possible connection between PCOS and endometriosis.