There is mounting evidence in support of carer involvement in the treatment of eating disorders (EDs) across the lifespan. In children and adolescents, randomized clinical trials provide robust findings supporting the active involvement of parents in the context of family-based therapy (FBT; for reviews, see Downs & Blow, 2013; Lock, 2011). FBT engages parents as key resources in the therapy and the FBT clinician is tasked with empowering parents to adopt a primary role in their child’s treatment process. Parental self-efficacy is emerging as a variable of particular interest in FBT. In a qualitative study exploring the core principles of FBT for adolescents with anorexia nervosa, clinicians identified parental self-efficacy as crucial for a positive outcome (Dimitropoulos, Freeman, Lock, & Le Grange, 2015). In the context of research, Lafrance Robinson, Strahan, Girz, Wilson, and Boachie (2013b) reported that, through the course of adapted FBT for adolescents with ED, positive changes in parental self-efficacy predicted reductions in their child’s ED, depression, and anxiety symptoms, which were maintained at three and six months post-treatment. Byrne, Accurso, Arnow, Lock, and Le Grange (2015) mirrored and extended these findings. The results of their study revealed that increases in parental self-efficacy predicted adolescent weight gain, whereas increases in self-efficacy in the adolescents themselves did not.