Emotional processing theory developed by E. B. Foa and M. J. Kozak (1986) has informed the conceptualization of anxiety disorders and the development of effective treatments for these disorders, including posttraumatic stress disorder (PTSD). This article presents a summary and update of emotional processing theory as it applies to the treatment of PTSD, data in support of this theory, and clinical examples of how the theory can be used to assist in the treatment of clients with PTSD. Common difficulties confronted during exposure therapy for PTSD, including underengagement and overengagement, are discussed in the context of emotional processing theory and suggestions for how to manage these difficulties are presented.