The purpose of this qualitative study was to explore the self-efficacy of registered dietitian nutritionists working with clients with eating disorders (ED) and factors that might influence efficacy. Three focus groups (n = 16) were held with registered dietitian nutritionists at the 2013 Academy of Nutrition and Dietetics Food and Nutrition Conference and Expo. Open coding identified several themes: challenges with clients' mental health, treatment apprehension, blurred practice boundaries, poor ED awareness among professionals, need for mentor/colleague collaboration, minimal formal education on ED, and difficulty with protocol expectations for ED. Identification of these factors indicates a need for continued ED resource development for registered dietitian nutritionists to provide optimal care.