Agoraphobia is a condition that most often occurs in the context of panic disorder and is characterized by intense fear or anxiety of places or situations in which escape might be difficult or help might not be available in the event of a panic attack or panic-like symptoms (APA, 2000). The purpose of this paper is to examine the behavioral mechanisms that may be responsible for the development and maintenance of the disorder, as well as how the disorder can be treated. In particular, the effective use in vivo exposure is described. Key words: In Vivo Exposure, Agoraphobia, Behavioral Treatments, Anxiety Disorders.