Trichotillomania is characterized by the repetitive pulling out of one's own hair leading to hair loss and possibly functional impairment. Trichotillomania has been documented in the medical literature since the 19th century. Prevalence studies suggest that trichotillomania is a common disorder (point prevalence estimates of 0.5%-2.0%). Although grouped with the obsessive-compulsive disorder (OCD) in the diagnostic and statistical manual of mental disorders-5, trichotillomania is distinct from OCD in many respects. For example, the treatment of trichotillomania generally employs habit reversal therapy and medication (n-acetylcysteine or olanzapine), both of which are quite different from those used to treat OCD. Conversely, some first-line treatments used for OCD (e.g., selective serotonin reuptake inhibitors) appear ineffective for trichotillomania. This article presents what is known about trichotillomania and the evidence for a variety of treatment interventions.