It is common for individuals with symptoms of posttraumatic stress disorder (PTSD) to present with co-occurring pain problems, and vice versa. However, the relation between these conditions often goes unrecognized in clinical settings. In this paper, we describe potential relations between PTSD and chronic pain and their implications for assessment and treatment. To accomplish this, we discuss phenomenological similarities of these conditions, the prevalence of chronic pain in patients with PTSD, and the prevalence of PTSD in patients with chronic pain. We also present several possible explanations for the co-occurrence of these disorders, based primarily on the notions of shared vulnerability and mutual maintenance. The paper concludes with an overview of future research directions, as well as practical recommendations for assessing and treating patients who present with co-occurring PTSD or chronic pain symptoms.