Body dysmorphic disorder (BDD) is a syndrome characterized by distress secondary to imagined or minor defects in one's appearance. Body dysmorphic disorder (BDD), also known as dysmorphophobia, is a severe psychiatric disorder that occurs around the world. It is relatively common and the diagnosis is usually missed. There is mounting evidence indicating that reactive oxygen species (ROS) are involved in initiation and development of many different forms of some neuropsychiatric disorders. The human body has some antioxidants such as catalase, glutathione peroxidase, superoxide dismutase against ROS. A common functional polymorphism was identified in the human catalase gene promoter, consisting of a C to T substitution in position -262 which causes to increased basal expression levels in different cell types and higher enzyme activity in red blood cells. In this study, we explored the relationship between catalase -262C-->T polymorphism and body dismorfic disorder with RFLP method and the first results are presented.