Background: Chronic pain is a common condition among older adults. While cognitive behaviour therapy (CBT) has been tested in numerous studies on adults and children there are fewer studies on older persons. The objective of this study was to investigate the effects of a six-session CBT group treatment for older persons with chronic pain. As a secondary aim we investigated whether treatment credibility was associated with outcome. Method: We included 21 persons (mean age = 72.0 years) who were randomly allocated to either a waitlist condition or treatment consisting of applied relaxation, with the addition of problem solving, assertiveness, communication strategies, sleep management, and relapse prevention. Results: Few statistically significant effects were found on measures of pain, mood, anxiety, and quality of life; however, a significant treatment effect with a between group effect size of d = 1.0 was observed with respect to perceived ability to function despite the discomfort of pain. Conclusion: The study provides some preliminary support for the use of group-based CBT with a focus on applied relaxation for older adults with chronic pain.