Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies and it manifests itself in about 4-12% women of reproductive age. The Rotterdam, AES and NIH criteria can be used to diagnose PCOS in adults but there are no specific criteria to diagnose PCOS in adolescent girls. Most authors agree that applying criteria for adult to teenagers leads to overdiagnosis because of similarity in physiological changes during puberty and common PCOS symptoms. Tightening of the current criteria and including new, not widely accepted yet, was proposed. Currently it seems justifiable to diagnose PCOS in adolescent girls using the Rotterdam criteria, on condition that all three symptoms are present, hyperandrogenism is established in laboratory tests and pelvic ultrasound reveals an increased ovarian volume (> 10 ml). Nevertheless, the necessity of more research and establishing specific criteria for adolescent girls is emphasized.