Many adolescents present with hirsutism and irregular menses. The challenge for the clinician is to distinguish physiologic anovulatory cycles from true menstrual disorders such as PCOS, and to differentiate PCOS from other causes of hyperandrogenism in hirsute adolescents. Common clinical features seen in adolescents with PCOS include hirsutism, acne, menstrual irregularity, and obesity. Biochemical abnormalities include hyperandrogenism, acyclic estrogen production, LH hypersecretion, decreased levels of SHBG, and hyperinsulinemia. Management strategies for a patient with PCOS include treatment of features which may cause distress to the adolescent, such as hirsutism, acne, and irregular menses, and prevention of long-term sequelae. Oral contraceptive pills, antiandrogens, and cosmetic treatments are used to treat hirsutism, acne, and menstrual irregularity. Oral contraceptive pills or medroxyprogesterone acetate are given to prevent endometrial hyperplasia and carcinoma. Counseling about weight loss and nutrition are essential, as weight loss may improve signs of hyperandrogenism and menstrual irregularity and may prevent NIDDM and cardiovascular disease. Insulin-sensitizing agents show promise in terms of decreasing hyperandrogenism, restoring ovulatory cycles, treating infertility, and preventing long-term sequelae. Finally, it is important to recognize that adolescents with PCOS may experience psychological distress because of the clinical manifestations of hyperandrogenism or when confronted with the information that they have a chronic illness. Psychological support should be available for these young women. Future research is likely to further elucidate the pathophysiology of PCOS, identify candidate genes, and clarify which adolescents are at risk for long-term sequelae. Prospective studies are needed to identify which therapies could potentially reduce the risk of infertility, diabetes, cardiovascular disease, and endometrial carcinoma in young women with PCOS.