Polycystic Ovary Syndrome (PCOS) is the most common endocrine disorder affecting up to 5–10% of women within the reproductive age group. PCOS is characterized by menstrual dysfunction and hyperandrogenism and is associated with a number of adverse metabolic outcomes. These women have an increased risk of diabetes and heart disease independent of body weight. Also, these women have difficulties in conceiving secondary to inefficient ovulation. With the epidemic of obesity, the PCOS phenotype is becoming ever more so prevalent and represents a clear and present health issue that needs to be addressed urgently. The information presented within this book describe for the first time the expression of novel adipocyte secreted factors termed ‘adipokines’ and the potential role that these novel adipokines may have in the context of the metabolomics of PCOS.