Many studies demonstrate increased androgen levels and high prevalence of polycystic ovaries in women affected by acne. We evaluated the relationship between clinical features, ultrasonographic data on polycystic ovaries and hormonal parameters in 129 women >17 years of age with acne. Serum levels of androgens of ovarian and adrenal origin were measured. Menstrual cycle regularity, hirsutism, body mass index and ultrasonographic evaluation of ovaries were recorded. Raised levels of at least one androgen were evident in a majority of our patients. Only 19% of them had polycystic ovary syndrome. Hirsutism and acne severity correlated negatively with serum sex hormone-binding globulin (SHBG) levels (p<0.05). No correlation between acne severity and hirsutism was found. In post-pubertal women, severity of acne seems to depend on peripheral hyperandrogenism, with a negative relationship between the acne severity and serum SHBG levels. We strongly recommend the evaluation of serum SHBG levels in women with acne in order to select patients who can have a better response to appropriate hormonal regimes.