Insulin resistance is defined as a subnormal biological response to insulin exposure and may be observed on different body levels. It has become the major health problem of our times. Associated obesity, dyslipidemia, atherosclerosis, hypertension, and type 2 diabetes conspire to shorten life spans, while hyperandrogenism with PCOS affect the quality of life and fertility of increasing numbers of women. Polycystic Ovary Syndrome (PCOS) or functional ovarian hyperandrogenism, is considered as the most frequent cause of hormonal disorder and infertility. It is associated with characteristic metabolic disturbances (resistance to the action of the insulin) that may have an important implication for long term health.Insulin resistance and PCOS share the same pathogenic origin and many factors may cause the genesis of this disease such as: inheritance factor, any factor regulating gonadotropin secretion or action, adrenal or ovarian steroidogenesis or extragonadal aromatization cell dysfunction and obesity.A growing numbers of individuals affected by this disease require early detection and medical intervention from childhood. The reversal of insulin resistance in PCOS patients constitutes the fundamental goal in the management of hyperandrogenism, infertility, acne and hirsutism. Insulin sensitizers (Metformin) are playing a significant role in the treatment of this disease.