Cognitive-behavioral models suggest that certain cognitions and beliefs are functionally related to hair pulling in persons with trichotillomania (TTM), but little empirical data have been collected to test such claims. This study assessed dysfunctional beliefs about appearance, shameful cognitions, and fear of negative evaluation and their relation to hair-pulling severity in a sample of individuals self-reporting a diagnosis of TTM. Results showed significant correlations between these cognitions and hair-pulling severity; however, relations diminished or disappeared when controlling for experiential avoidance, a tendency to avoid or escape from unwanted private events. These findings suggest that treatments targeting cognitions may benefit from focusing on experiential avoidance more broadly. (Contains 3 figures and 2 tables.)