PCOS represents the commonest endocrinopathy among women of reproductive age. We conducted this study to evaluate the association between polycystic ovaries and clinical and biochemical features of the syndrome. TVS was performed in 74 women with the clinical diagnosis of PCOS. The findings were compared to biochemical, hormonal and clinical features of the syndrome. Statistical analysis revealed a significantly higher prevalence of acne, LH/FSH ratios and testosterone levels in women with PCO compared to those with normal ovarian morphology. In the subgroup analysis, total ovarian volume correlated significantly with hirsutism scores. Our study revealed a great prevalence of polycystic ovaries in Greek women with PCOS, and emphasizes the significance of transvaginal ultrasound in establishment of the diagnosis of the syndrome. The presence of PCO may not be clinically important when present alone without clinical manifestations but reflects the underlying hyperandrogenemia in PCOS women, representing a useful tool in the management of these patients.