Nonsuicidal self-injury (NSSI) affects a growing number of youth and transitional-aged youth. Nock's (2009) comprehensive model of NSSI engagement points to a range of factors that combine to predict who is at a heightened risk for self-injury. The present study examined the impact of specific interpersonal factors, family communication patterns (i.e., conversation and conformity orientations), and communication competence on five supported measures of self-injurious behaviors. We further tested whether alexithymia, or a person's inability to identify and describe their emotions, mediated family communication patterns and communication competence in predicting NSSI behavior. Family communication patterns, specifically conversation orientation, had a positive impact on lifetime NSSI behaviors. While communication competence positively related to both lifetime and current NSSI behaviors, alexithymia mediated these relationships. Implications for treatment are provided.