Objective: To determine if polycystic-appearing ovaries (PAO) are associated with differences in risk factors for cardiovascular disease among women with polycystic ovary syndrome (PCOS). Design: Case-control sub-study. Setting: Division of Reproductive Endocrinology, Magee-Womens Hospital. Patient(s): Women with PCOS (n = 63) and non-PCOS controls (n = 56). Intervention: Transvaginal ultrasonography and single sample venipuncture. Main Outcome Measure(s): Ultrasound ovarian appearance, fasting insulin, lipoproteins, androgens, LH/FSH ratio, anthropomorphic measurements, and blood pressure. Result(s): Women with PCOS had higher androgen and fasting insulin levels, a more adverse lipid profile, greater waist-hip and LH/FSH ratios, and a larger ovarian volume than controls. Thirty-three percent of the cases with PCOS, but only 5% of controls, showed PAO on ultrasound study (P < .01). PCOS cases with and without PAO had comparable levels of fasting insulin, lipids, and blood pressures. PCOS cases with PAO had a higher LH/FSH ratio (P = .028), increased levels of serum androstenedione (P = .029) and testosterone (P = .055), and greater ovarian volume (P = .024) compared to non-PAO patients. Conclusion: Women with PCOS have greater cardiovascular risk than controls. Within PCOS cases, however, the ultrasound appearance of polycystic ovaries does not appear to further intensify the cardiovascular disease risk profile of these women. (Fertil Steril(R) 2000,74:547-52. (C) 2000 by American Society for Reproductive Medicine.).