The issue of maladaptive behavior, as an associated consequence of traumatic brain injury (TBI), is one of the most important aspects in brain injury rehabilitation because behavior disorders, often, represent a significant barrier to effective rehabilitation and functional outcome. This chapter clearly illustrates the concepts, techniques, and uses of applied behavior analysis with those suffering from TBI. The person with TBI represents a special challenge to rehabilitation professionals and family members. It is now widely recognized that pharmacological intervention for behavioral disorders with the postacute patient with TBI is not necessarily the treatment of choice. Applied behavior analysis (sometimes referred to as behavior modification) has always been plagued by controversy. The basic principles of applied behavior analysis are relatively easy to understand. To begin with, all target behaviors (those behaviors to be modified) are preceded by some event in the person's environment. This preceding event is called the antecedent. An antecedent event is followed by the occurrence of a behavior.