This study was designed to investigate the relative efficacy of cognitive-behavioral group treatment, including relaxation training, in comparison with a control condition in a sample of 20 outpatients with chronic low back pain. Subjects in both conditions also received the same physiotherapy back-education and exercise program. The control condition included a control for the attention of the therapist in the cognitive-behavioral treatment. The combined psychological treatment and physiotherapy condition displayed significantly greater improvement than the attention-control and physiotherapy condition at post-treatment on measures of other-rated functional impairment, use of active coping strategies, self-efficacy beliefs, and medication use. These differences were maintained at 6 month follow-up on use of active coping strategies and, to a lesser degree, on self-efficacy beliefs and other-rated functional impairment.