Polycystic Ovarian Syndrome (PCOS) is the most common endocrine disorder in women and affect 6-14% of women in reproductive age. The main feature of PCOS is polycystic ovaries producing an excessive amount of androgen hormones, resulting in irregular menstruation and anovulation. Clinically it may result in infertility, hirsutisme and acne. In addition, PCOS is associated with insulin resistance and obesity resulting in an increased frequency of Diabetes II. PCOS is the most common cause of anovulatory infertility and ovulation induction is the first infertility treatment for women with polycystic ovarian syndrome. The success in a treatment of infertility may be achieved by different options like weight loss, clomiphene citrate, dexamethason, aromatase inhibiters and IVF. The goal of this paper is to review the disease mechanisms, how PCOS may affect fertility and how to treat PCOS-associated infertility.