Polycystic ovary syndrome (PCOS) is recognized as the most common endocrine disorder of reproductive-aged women around the world. This document, produced by the collaboration of the American Association of Clinical Endocrinologists and the Androgen Excess Society aims to highlight the most important clinical issues confronting physicians and their patients with PCOS. It is a summary of current best practices in 2014. Insulin resistance is believed to play an intrinsic role in the pathogenesis of PCOS. The mechanism by which insulin resistance or insulin give rise to oligomenorrhea and hyperandrogenemia, however, is unclear. Hyperinsulinemic-euglycemic clamp studies have shown that both obese and lean women with PCOS have some degree of insulin resistance. Insulin resistance is implicated in the ovulatory dysfunction of PCOS by disrupting the hypothalamic-pituitary-ovarian axis. Given the association with insulin resistance, all women with PCOS require evaluation for the risk of metabolic syndrome (MetS) and its components, including type 2 diabetes, hypertension, hyperlipidemia, and the possible risk of clinical events, including acute myocardial infarction and stroke. Obese women with PCOS are at increased risk for MetS with impaired glucose tolerance (IGT; 31 to 35%) and type 2 diabetes mellitus (T2DM; 7.5 to 10%). Rates of progression from normal glucose tolerance to IGT, and in turn to T2DM, may be as high as 5 to 15% within 3 years. Data suggest the need for baseline oral glucose tolerance test every 1 to 2 years based on family history of T2DM as well as body mass index (BMI) and yearly in women with IGT. Compared with BMI- and age-matched controls, young, lean PCOS women have lower high-density lipoprotein (HDL) size, higher very-low-density lipoprotein particle number, higher low-density lipoprotein (LDL) particle number, and borderline lower LDL size. Statins have been shown to lower testosterone levels either alone or in combination with oral contraceptives (OCPs) but have not shown improvement in menses, spontaneous ovulation, hirsutism, or acne. Statins reduce total and LDL cholesterol but have no effect on HDL, C-reactive protein, fasting insulin, or homeostasis model assessment of insulin resistance in PCOS women, in contrast to the general population. There have been no long-term studies of statins on clinical cardiac outcomes in women with PCOS. Coronary calcification is more prevalent and more severe in PCOS than in controls. In women under 60 years of age undergoing coronary angiography, the presence of polycystic ovaries on sonography has been associated with more arterial segments with >50% stenosis, but the relationship between PCOS and actual cardiovascular events remains unclear. Therapies for PCOS are varied in their effects and targets and include both nonpharmacologic as well as pharmacologic approaches. Weight loss is the primary therapy in PCOS--reduction in weight of as little as 5% can restore regular menses and improve response to ovulation- inducing and fertility medications. Metformin in premenopausal PCOS women has been associated with a reduction in features of MetS. Clamp studies using ethinyl estradiol/drosperinone combination failed to reveal evidence of an increase in either peripheral or hepatic insulin resistance. Subjects with PCOS have a 1.5-times higher baseline risk of venous thromboembolic disease and a 3.7-fold greater effect with OCP use compared with non-PCOS subjects. There is currently no genetic test to screen for or diagnose PCOS, and there is no test to assist in the choice of treatment strategies. Persistent bleeding should always be investigated for pregnancy and/or uterine pathology--including transvaginal ultrasound exam and endometrial biopsy--in women with PCOS. PCOS women can have difficulty conceiving. Those who become pregnant are at risk for gestational diabetes (which should be evaluated and managed appropriately) and the microvascular complications of diabetes. Assessment of a woman with PCOS for infertility involves evaluating for preconceptional issues that may affect response to therapy or lead to adverse pregnancy outcomes and evaluating the couple for other common infertility issues that may affect the choice of therapy, such as a semen analysis. Women with PCOS have multiple factors that may lead to an elevated risk of pregnancy, including a high prevalence of IGT--a clear risk factor for gestational diabetes--and MetS with hypertension, which increases the risk for pre-eclampsia and placental abruption. Women should be screened and treated for hypertension and diabetes prior to attempting conception. Women should be counseled about weight loss prior to attempting conception, although there are limited clinical trial data demonstrating a benefit to this recommendation. Treatment for women with PCOS and anovulatory infertility should begin with an oral agent such as clomiphene citrate or letrozole, an aromatase inhibitor.