Greater acceptance of chronic pain is associated with lesser levels of pain-related distress and disability and better overall functioning. Pain acceptance is most often assessed using the Chronic Pain Acceptance Questionnaire (CPAQ), which includes both an eight-item short form (CPAQ-8) and a twenty item parent measure (CPAQ-20). This study derived a two-item CPAQ for use in busy clinical settings and for repeated measurement during treatment, the CPAQ-2. An Item Response Theory approach was used to identify the strongest items from the CPAQ-20, one from each of its two subscales. Next, regression analyses were conducted to evaluate the utility of the CPAQ-2 by examining variance accounted for in the CPAQ-8, CPAQ-20, and in measures of depression, pain-related fear, physical disability, and psychosocial disability. Four clinical databases were combined (N = 1776) for the analyses. Items 9 and 14 were identified as the strongest CPAQ-20 items in the IRT analyses. The sum score of these two items accounted for over 60% of the variance in the CPAQ-8 and CPAQ-20. Furthermore, this score accounted for significant variance in measures of depression, pain-related fear, physical disability, and psychosocial disability after controlling for data collection method (i.e., in clinic or online), participant age, education, pain duration, and usual pain. Finally, the amount of variance accounted for by the CPAQ-2 was comparable to that accounted for by both the CPAQ-8 and CPAQ-20. These results provide initial support for the CPAQ-2 and suggest that it is well suited as a brief assessment of chronic pain acceptance.