Polycystic ovarian syndrome (PCOS) is a clinical syndrome characterized by irregular menstrual cycles, signs of androgen access including hirsutism and acne, and infertility, with ovaries showing cystic changes. Many women with this condition are obese, and it is now well established that insulin resistance makes up a very important component of this syndrome. Recently, there has been increased focus on sleep-disordered breathing (SDB) in patients with PCOS. Several articles recently published have shown clearly, increased incidence of SDB in patients with PCOS. In this review, we shall explore the inter-relationship between the pathophysiology of PCOS and SDB.