Trichotillomania (TTM) is a complex disorder that is difficult to treat as few effective therapeutic options exist. Behavior therapy has the greatest empirical support, but the number of mental health providers familiar with TTM and its treatment is quite small. This manual was written as atool for therapists to become familiar with an effective treatment for TTM. The treatment approach described in this guide blends traditional behavior therapy elements of habit reversal training and stimulus control techniques with the more contemporary behavioral elements of Acceptance and Commitment Therapy (ACT). In the first phase of the program, clients are taughtskills for stopping and preventing their unconscious pulling episodes. In the second phase, clients are introduced to ACT. Unlike traditional interventions that aim to change type or frequency of pulling-related cognitions in the hopes of reducing urges to pull hair, this innovative program usesstrategies to change the function of these cognitions. Clients are taught to see urges for what they really are and to accept their pulling-related thoughts, feelings, and urges without fighting against them. This is accomplished through discussions about the function of language and defusionexercises that show the client how to respond to thoughts about pulling less literally. Over the course of 10 weeks, clients learn to be aware of their pulling and warning signals, use self-management strategies for stopping and preventing pulling, stop fighting against their pulling-related urgesand thoughts, and work toward increasing their quality of life. Self-monitoring and homework assignments keep clients motivated and engaged throughout.