Objective: To evaluate the metabolic profiles of adolescents with different phenotypes of polycystic ovary syndrome (PCOS). Design: Observational study. Setting: University outpatient clinic. Patient(s): Adolescents with PCOS (n = 120) were divided into four groups: oligomenorrhea and hirsutism (O-H, n = 50), oligomenorrhea, hirsutism, and polycystic ovaries (PCO-O-H, n = 22), oligomenorrhea, hirsutism, and hyperandrogenemia (A-O-H, n = 28), oligomenorrhea, and hirsutism, hyperandrogenemia, and polycystic ovaries (PCO-A-O-H, n = 20). A control group of age-matched adolescents (n = 30) was included. Intervention(s): Subjects underwent physical and ultrasound evaluations; fasting blood samples were taken for the measurement of endocrine and metabolic parameters. Main Outcome Measure(s): The endocrine and metabolic profiles were evaluated. Result(s): Adolescents with PCOS showed reduced insulin sensitivity and dyslipidemia. Triglycerides, and total and low-density lipoprotein cholesterol were higher in the phenotypes with hyperandrogenemia. Insulin resistance and body mass index were not significantly different between PCOS phenotypes. Triglyceride positively and high-density lipoportein cholesterol levels negatively correlated with free testosterone and free androgen index. Conclusion(s): The risk of metabolic alterations may vary in adolescent PCOS patients with different phenotypes. Hyperandrogenemia is a risk factor for dyslipidemia. This information may be of relevance in counseling adolescents with PCOS. (Fertil Steril (R) 2009;92:626-34. (C)2009 by American Society for Reproductive Medicine.)