Within third-generation therapies, acceptance and commitment therapy (ACT) has been enshrined as one of the most effective, given its excellent results and the multitude of areas to which it can be applied. In general, this therapy is intended to break the pattern of experiential avoidance, which means responding literally to the content of aversive private events. The present study presents an intervention with ACT in a problem of trichotillomania in a patient, L., 17 years of age. After 10 intervention sessions in which all the components of ACT are worked on (creative hopelessness, defusion, clarification of values, self as context, contact with the present moment, etc.), there are more actions aimed at achieving the values, and although a reduction in discomfort is not reported, L. is able to contemplate private events without literally responding to their presence.