Conducting a behavior analysis is a common diagnostic procedure in behavior therapy. It provides a dysfunction-independent working model for the behavioral and multimodal exploration of the patient’s condition as well as subsequently an important basis for the preparation of a case concept. Starting from a definition of behavior analysis the components of a behavior analysis as well as their differentiations are introduced. Subsequently, a well-established practical procedure of a behavior analysis is exemplarily demonstrated by means of a case study. Finally, the current significance of this technique is discussed for therapeutic purposes.