Parents' responses to their children's emotional expressivity have been shown to significantly influence children's subsequent psychosocial functioning. This study hypothesized that adolescents' deliberate self-harm (DSH) may be an outcome associated with poor emotion regulation as well as an invalidating family environment. The mediational role of specific emotion processes (i.e., poor awareness of emotion, difficulties expressing emotions) between family emotional environment and the frequency of DSH was examined with 131 psychiatrically hospitalized adolescents (M age = 14.84 years, SD = 1.75 years). Results indicated that adolescents who self-injured reported that this behavior reduced their negative emotional states. Structural equation modeling provided support for the proposed model that family climate influences frequency of DSH through emotion regulation skills but the model held for girls only. A direct model effect was not supported. Emotion regulation partially mediated the relationship between family climate and DSH, and direct effects were also observed.