Much overlap is present between the polycystic ovary syndrome (PCOS) and the metabolic syndrome. This article reviews the existing data regarding the prevalence, characteristics, and treatment of the metabolic syndrome in women with PCOS. The prevalence of the metabolic syndrome in PCOS is approximately 43-47%, a rate 2-fold higher than that for women in the general population. High body mass index and low serum HDL cholesterol are the most frequently occurring components of the metabolic syndrome in PCOS. The pathogenic link between the metabolic syndrome and PCOS is most likely insulin resistance. Therefore, the presence of the metabolic syndrome in PCOS suggests a greater degree of insulin resistance compared to PCOS without the metabolic syndrome. Obesity, atherogenic dyslipidemia, hypertension, impaired fasting glucose/impaired glucose tolerance, and vascular abnormalities are all common metabolic abnormalities present in PCOS. Lifestyle modification has proven benefit and pharmacological therapy with insulin-sensitizing agents has potential benefit in the treatment of the metabolic syndrome in women with PCOS.