Nail biting (NB) is a common, but unresolved, problem in psychiatry, psychology, medicine and dentistry. While it seems Nail biting (NB) has been a less-published area in the literature of both of psychiatry and dermatology.1,2 Medicine, psychology and dentistry have been unable to resolve the problem of NB.3 While individuals who practice NB usually like to stop it, their efforts to put an end to it have failed. The parents of a sizable number of children, whom are referred to clinics for the management of NB, have tried to help their children by means such as coating nail plate with substance that have unpleasant taste. Sometime they have covered the nails with rubber or cloth finger protectors. These measures do not usually lead to a permanent fading of this behavior. Many of children with NB behavior may be punished by their parents or family members. Punishment and threat may not lead to the decrease of NB frequency, in fact may lead to an increase in it. Sometimes, individuals with NB behavior may say that they are powerless or unable to stop this unwanted behavior. There is a speculation that NB may guide clinicians to a better pharmacological management of children with attention deficit hyperactivity disorder (ADHD).