Polycystic ovary syndrome (PCOS) affects 5% to 10% of women of reproductive age, with symptoms often presenting during adolescence and young adulthood. It is a condition characterized by 1) hyperandrogenism, 2) oligomenorrhea or amenorrhea, and 3) polycystic ovaries. This syndrome is associated with significant endocrine, metabolic, cardiovascular, reproductive, and psychiatric morbidities. Although the diagnosis of PCOS is based on the presence of at least 2 of the 3 criteria that characterize the condition, the syndrome has a broad spectrum of clinical features that may signal its presence. Evidence suggests that many women with clinical features of PCOS remain undiagnosed, placing them at an increased risk for developing complications associated with the syndrome. This review presents current information about the pathophysiology, clinical features, diagnosis, and recommended treatments for PCOS.