Tourette's Syndrome (TS) and Trichotillomania (TTM) are both subsumed under a larger category of repetitive behavior disorders. The purpose of this paper is to provide an overview of the most recent behavioral research on TS and TTM. A description of both disorders is provided along with the most recent research on their etiology and maintenance. Behavioral treatments are then discussed with an emphasis on habit reversal--a multi-component procedure shown to be effective for treating repetitive behavior disorders. In addition, research analyzing the relative efficacy and importance of each habit reversal component is discussed. The review then concludes with treatment considerations.