Hirsutism represents a primary clinical indicator of androgen excess. The most common endocrine condition causing hirsutism is polycystic ovary syndrome (PCOS). Diagnosing PCOS is not easy as the signs and symptoms are heterogenous. The newest diagnostic guideline made by the Androgen Excess and PCOS Society in 2006, claims the presence of hyperandrogenism, and ovarian dysfunction (oligo / anovulation and / or polycystic ovaries). Obesity associated reproductive and metabolic dysfunctions may aggravate the symptoms of PCOS. PCOS might be underdiagnosed in non obese women because lean PCOS phenotypes might be underestimated for the syndrome. Effective medical treatment of PCOS and associated hirsutism depends on the endocrinological expertise and experience of the therapist in each individual case. An algorithm for the treatment has not been established yet.