Body Dysmorphic Disorder (BDD) is an excessive preoccupation with an imagined, or real, slight defect in normal physical appearance. The disorder, which usually begins during adolescence, tends to be chronic, and probably is much more common than is usually thought. This review presents an overview of the available scientific literature of BDD. It provides information about historical aspects, epidemiology, clinical features, aetiology, and instruments for assessing BDD. The relationship of BDD with other psychiatric disorders such as depression, obsessive-compulsive disorders, anxiety disorders, schizophrenia, eating disorders and personality disorders is discussed. Aetiological theories, including psychological and neurobiological explanations, are reviewed. Finally, psychopharmacological and psychotherapeutic treatment approaches are presented with special regard to treatment with serotonin-reuptake inhibitors, behavioural therapy and cognitive-behavioural therapy.