Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism, chronic anovulation, and oligomenorrhea (O/M). PCOS has variable clinical phenotypes, biochemical features, and metabolic abnormalities. To determine the prevalence of PCOS in the Greek population as well as the metabolic parameters, we performed a cross-sectional study of 192 women of reproductive age (17-45 yr), living on the Greek island of Lesbos. They were divided into 4 groups according to the presence of hirsutism (defined as a Ferriman-Gallwey score > or = 6) and O/M: group N (n = 108), regular menses and absence of hirsutism; group 1 (n = 56), regular menses and hirsutism; group 2 (n = 10), O/M and absence of hirsutism; and group 3 (n = 18), O/M and hirsutism. Body mass index, waist to hip ratio, and mean blood pressure did not differ among the studied groups. Hormonal profile was assessed by measuring free testosterone (FT). The prevalence of PCOS, defined by the presence of O/M and biochemical hyperandrogenism (FT > or = 95th percentile of the normal women), was estimated to be 6.77% (13 women of 192). Higher FT levels were observed in group 3 (O/M and hirsutism) compared with groups N (P < 0.00001) and 1 (P < 0.0001) and in groups 1 (hirsutism) and 2 (O/M) compared with group N (P < 0.0001 and P < 0.005, respectively). Sex hormone-binding globulin levels were lower in women with PCOS and in groups 1 and 3 than those in group N (P < 0.002, P < 0.02, and P < 0.002, respectively) independently of the body mass index. The metabolic profile was investigated by measurements of fasting glucose (FG), fasting insulin (FI), and estimation of the fasting glucose to insulin ratio (FG:I ratio). After covariance adjusted for the BMI, FI levels were higher in group 3 and in women with PCOS than in the normal (P < 0.005 and P < 0.002, respectively) and the hirsute (P < 0.05 and P < 0.02, respectively) women, whereas FG levels did not differ among the studied groups. The FG:I ratio was lower in group 3, group 1, and in women with PCOS than in normal women (P < 0.05). Finally, a high incidence of family history of diabetes mellitus (P = 0.001) and menstrual disorders (P = 0.01) was observed in women with PCOS, in contrast to the normal and hirsute women. In conclusion, PCOS appears to be a particularly common endocrine disorder in the Greek population under study (prevalence, 6.77%); furthermore, it is associated with certain metabolic abnormalities. These data also suggest that the severity of the fasting hyperinsulinemia is associated with the severity of the clinical phenotype of hyperandrogenism independently of obesity.