Polycystic ovary syndrome (PCOS) is a mysterious reproductive disorder that results in subfertility. The underlying causes are not known, and even the definition is a moving target. Women with epilepsy have features of PCOS at a higher than expected rate, and polycystic ovaries (PCO) also are present at high rates in this population. Valproate is associated with weight gain and increased androgen levels, two features of PCOS. This review proposes that epilepsy, with its known adverse effects on luteinizing hormone pulsatility, could be a cause of PCOS and that valproate could be an imitator, if not also a cause of the syndrome.