Objective.This study was designed to assess the diagnostic potency of different androgens in hyperandrogenaemia criterion on polycystic ovary syndrome (PCOS) based on receiver operator characteristic (ROC) curves analysis. Methods.We evaluated 55 PCOS patients and 27 healthy fertile women (control). Androgen evaluation included bio-available testosterone (BAT) by ammonium sulphate precipitation, Free Testosterone Index (FTI), androstenedione (A), total testosterone and dehydroepiandrosterone sulphate (DHEA-S). Results.The androgen tests with the best diagnostic capacities were FTI and BAT. Although T and A had similar diagnostic potencies, A detected 5 of PCOS patients that could not be recognised by FTI, BAT (), or T. The association of FTI, BAT () and A identified 96.36 of the hyperandrogenaemic patients. DHEA-S showed a wide dispersion of values and therefore poor discriminatory competence. Discussion.This study suggests that routine androgen evaluation in PCOS should include FTI, B