Nail biting (onychophagia) is a common disorder which has not been investigated yet. There are different opinions about to classify onychophagia, but according to DSM-IV-TR it is classified as impulse control disorder not otherwise specified. The knowledge about treatment of onychophagia is limited. There are a few studies about treatment of onychophagia with psychotherapy and a study with pharmacotherapy. Some studies suggest that an atypical antipsychotic aripiprazole may have beneficial effects in the treatment of impulse control disorders. In this study we report a case of onychophagia which has successfully treated with aripiprazole add-on to escitalopram treatment that has never reported before.