Family-based treatment (FBT) is the leading treatment for adolescent eating disorders and is based on five tenets, or fundamental assumptions: (1) the therapist holds an agnostic view of the cause of the illness; (2) the therapist takes a non-authoritarian stance in treatment; (3) parents are empowered to bring about the recovery of their child; (4) the eating disorder is separated from the patient and externalized; and (5) FBT utilizes a pragmatic approach to treatment. Learning these tenets is crucial to the correct practice and implementation of manualized FBT. The purpose of the current paper is to provide an in-depth overview of these five tenets and to illustrate how they are used in clinical practice. This overview will aid clinicians who are learning FBT.