This book focuses on World clinics obstetrics and Gynecology: Polycystic ovary Syndrome”. Polycystic ovary syndrome (PCOS) is a heterogeneous and complex disorder with varied collection of signs and symptoms so as no single test is diagnostic. It is a genetically determined, primary ovarian disorder resulting in excess androgen production. It has both adverse reproductive and metabolic implications for affected women. This book comprises of nine chapters, which consists of pathophysiology of PCOS, diagnosis of PCOS, menstrual abnormalities, obesity and metabolic syndrome, fertility treatment, pregnancy complications, depression, anxiety, and eating disorders, cosmetic concerns, and abnormal uterine bleeding. The diagnostic criterions of PCOS are polycystic ovarian morphology (PCOM) on ultrasound, increased ovarian volume, and raised levels of anti-Müllerian hormone (AMH). Treatment of oligomenorrhea or ovulation is by achieving an ideal BMI. Metformin therapy is ideal as it reduces insulin resistance and promotes weight loss. Reproductive gratification is achieved with induction of ovulation in the majority of cases with, clomiphene citrate, aromatase inhibitors, and/or gonadotropins.