C hronic pain has been viewed through a variety of lenses and perspectives over the last century. For example, approximately 50 years ago, chronic pain was viewed by clinicians in much the same way as acute pain. Namely, clinicians believed that once an injury healed, pain would resolve, and if it failed to resolve, the problem was viewed as "psychological" rather than physical. Naturally, this conclusion was quite distressing to patients whose pain persisted; these patients felt their pain was real and not simply "in their heads." However, our current understanding of the etiology of chronic pain has greatly evolved. We are now aware of how biological, psychological, and social factors can impact the experience of pain, and how to address these factors in order to best alleviate suffering. Cognitive behavioral therapy (CBT) for chronic pain now has substantial empirical support, is considered an evidence-based treatment, and is widely used as stand-alone treatment or as part of multidisciplinary pain treatment programs. Research has contributed to our understanding of the various factors that should be considered when providing CBT and, more recently, is focusing on ways in which clinicians can tailor CBT to the specific needs of each patient in order to maximize treatment efficacy.The primary aim of this chapter is to provide a thorough review of the literature on chronic pain and efficacious psychological treatments for pain, focusing on cognitive behavioral approaches. The chapter begins with a review of the definitions of pain, as well as the different types of pain that can be experienced, and data on the prevalence and costs associated with chronic pain.