Unrelieved pain can result in excessive diagnostic tests, increased outpatient services and decreased ability to function, resulting in lost income and disability. While acute pain is normal indicating possible injury, chronic pain associated with a wide array of conditions (e.g., cancer, arthritis) and specific disorders (e.g., low back pain, painful diabetic neuropathy) is different and persists. Pain is typically assessed by a self-report of severity, but severity is too narrow to capture its complexity and impact. Patient Reported Outcomes Measurement Information System (PROMIS) is a system of reliable, precise and flexible measures of patient–reported health status. PROMIS has developed several specific pain item banks and measures including pain intensity, quality, interference, and behaviors. However, two important pain-related domains are missing from PROMIS: Pain Catastrophizing (PC) and Pain-Related Self-efficacy (PRSE). Pain catastrophizing refers to the exaggerated negative thoughts and feelings about pain that some people have when they are in pain (e.g., because of my pain, my life is over). PC is a form of “cognitive distortion” that is hypothesized to contribute to the development and maintenance of depression and negative affect. Understanding and measuring the belief that people with chronic pain can successfully self-manage and live effectively with pain (i.e., PRSE) is important for designing treatments that can lead to an improved quality of life. Adding measures of these domains would greatly enhance the utility of PROMIS pain instruments for conducting comparative effectiveness research in chronic pain.