This paper outlines an amendment to current fear-avoidance models of chronic pain. These models propose that fear and avoidance behavior contribute significantly to the development and maintenance of chronic pain and related functional limitations. Fear is typically expressed in three response domains, including cognitive, behavioral, and physiological. To date, however, fear-avoidance models of chronic pain have focused primarily on the role of the cognitive and behavioral responses to the relative exclusion of the physiological response domain. This paper describes how states of physiological arousal resulting from autonomic nervous system activation (e.g., increased heart rate, increased blood flow to voluntary muscles, decreased blood flow to the gastrointestinal tract and to the skin, decreased motility, decreased cerebral blood flow) may influence fear of pain and avoidance behavior and thereby contribute to the maintenance of chronic pain. Clinical implications and future research directions are discussed.