PCOS is a syndrome of ovarian dysfunction accompanied by features of hyper-androgenism and polycystic ovary morphology. The Rotterdam criteria are the most widely accepted for clinically diagnosing PCOS. Prior to following this criteria, it is essential to exclude other aetiologies like hyperprolactinemia, androgen secreting tumors etc. According to the Rotterdam criteria, the patient should have at least 2 of the following 3: 1. Oligo/anovulation 2. Hyperandrogenism - clinical (hirsutism, male pattern alopecia) or biochemical (raised free androgen index or free testosterone) 3. Polycystic ovaries on ultrasound