There is a great need today for clinically useful instruments in the rehabilitation of chronic pain patients. The Arthritis Self-efficacy Scale measures patients' perceived self-efficacy to cope with the consequences of chronic arthritis. The aim of the present study was to evaluate a Swedish version of the Arthritis Self-efficacy Scale with respect to factor structure and reliability. Twenty-five chronic pain patients and twenty-four rheumatology patients were given a Swedish version of the Arthritis Self-efficacy Scale twice within a three week interval. The three factor structure of the scale was confirmed; Cronbach's alpha for internal consistency ranged between 0.82-0.91 and test-retest correlations ranged between 0.81-0.91, showing that the instrument satisfactorily met psychometric standards.