Chronic pain is a common problem that can be challenging to treat because of its complex history, unclear etiology, and poor response to traditional treatment approaches. A growing body of research suggests that behavioral activation (BA), which was originally developed as a treatment for depression, may be a promising treatment for chronic pain. BA involves the identification and enactment of activities that are reinforcing to the individual and consistent with his or her long-term goals. The application of BA for the treatment of chronic pain is fully consistent with models of chronic pain which post that fear and avoidance leads to a cycle of physical deconditioning, increased pain as a result of deconditioning, lack of positive reinforcement, and low mood, and further reduced motivation to physically engage. The present paper will detail the assessment and use of BA to treat “Veteran,” a patient with low back and bilateral foot pain. This case study highlights how gradually increasing engagement in previously avoided activities can help disrupt the harmful cycle among pain, fear and avoidance, and mood. The implication of the outcomes from this case study for future psychotherapy research on chronic pain is also discussed.