Polycystic Ovary Syndrome (PCOS) is a heterogeneous condition characterized by chronic anovulation and androgen excess that occurs in 4-8% of unselected adult women. Although signs and symptoms of the disorder typically appear at the time of puberty, diagnosis is often delayed until adulthood. At least 50% of adult women with PCOS are obese, resulting in a more severe clinical picture. Obesity among adolescents has been increasing in recent years, with overrepresentation of females who show evidence of hyperandrogenism and irregular periods, suggesting an association of obesity and PCOS at an early age. Recent data, however, have drawn attention to the long-term risks of PCOS, including diabetes and cardiovascular disease. Insulin resistance plays a critical role in the pathophysiology of PCOS and is thought to be the metabolic abnormality most closely linked to an increased risk of diabetes and heart disease. Traditional treatments with oral contraceptives are associated with reduction in serum androgens and improvements in menstrual cycles in adolescents with PCOS, however these have not been well-studied in obese adolescents. Oral contraceptives may worsen the dyslipidemia seen in obese women with PCOS and do not address the insulin resistance. Metformin, an insulin sensitizing agent, has been shown to improve metabolic features of PCOS, but combination therapy with oral contraceptives has never been studied in the obese adolescent with PCOS.