Previous research on trichotillomania (TTM) has demonstrated an emotion regulation function of hair pulling behavior. One condition that can impede the regulation of emotions is alexithymia. The present study aimed to explore the relationship between the degree of alexithymia and the severity of hair pulling behavior in individuals with TTM. Multiple strategies were used to recruit a sample of 105 participants via the internet. All participants were diagnosed with TTM by an experienced clinician via a subsequent phone-interview. Multiple linear regression analysis was performed to test the potential predictive value of the different facets of alexithymia (20-item Toronto Alexithymia Scale) on the severity of TTM (Massachusetts General Hospital Hair-Pulling Scale). Both the difficulty in identifying feelings (DIF) facet of alexithymia (p=0.045) and depression (p=0.049) were significant predictors of the severity of TTM. In conclusion, alexithymia seems to play a role in hair pulling behavior in individuals with TTM. However, the significant association was small in terms of the overall variance explained, thus warranting further research. If replicated in prospective studies, then these results indicate that therapeutic approaches aimed at supporting patients in recognizing and differentiating feelings might be useful for the treatment of TTM.