Recent findings suggest substantial metabolic sequelae to polycystic ovary syndrome (PCOS), including risk of diabetes and cardiovascular disease. Primary treatment of the metabolic sequelae should be the focus of the clinician. The definition of PCOS has been expanded from a disorder that presents at menarche and ends at menopause to a disorder that may be present from birth to senescence. The earliest recognized PCOS phenotype to date is premature pubarche characterized by excessively elevated levels of dehydroepiandosterone sulfate and hyperinsulinemia. Such girls are at high risk to develop the full PCOS phenotype, including ovarian hyperandrogenism and chronic anovulation. A fasting glucose-to-insulin ratio of < 7 is a useful index of insulin resistance in adolescents. However, each patient should be evaluated for glucose intolerance and lipid abnormalities on a regular basis by completing a 2-hour oral glucose tolerance test and a fasting lipid profile. Primary prevention of diabetes and cardiovascular disease by lifestyle modifications, regular exercise, and a balanced diet are of utmost importance, especially in adolescents who have the opportunity to establish healthy habits before entering adulthood. The role of insulin-sensitizing medications is still under study. Although no clinical trials over 6 months in duration have assessed the long-term efficacy of metformin use in adolescents, short-term trials have shown promising effects in lowering insulin secretion, improving insulin sensitivity, restoring normal menstrual cycles, and correcting lipid abnormalities.