Background and Design: Melasma is a common, symmetric hypermelanosis characterized by irregular brown to gray-brown macules on the face. It is frequently associated with pregnancy and oral contraceptive consumption. Sunlight and genetic factors play major roles in the pathogenesis of melasma. Human skin exposed to ultraviolet light or environmental oxidizing pollutants become a preferred target of oxidative stress. Topical and oral antioxidants are used to treat melasma. To investigate serum antioxidant capacity in patients with melasma and relationship between antioxidant levels and melasma severity.