Cognitive behavioral treatment has been incorporated into standard medical treatment procedures in German pain centers. Acceptance of the treatment by patients and outcome in terms of pain, coping, and disability was investigated. Components of the psychological treatment are education, relaxation and imagery, modifying thoughts and feelings, enhancement of pleasant activities, and training of good postural habits. The program was conducted in a group setting in accordance with a treatment manual and consists of 12 weekly 2.5-h sessions. A two-factor experiment with repeated measures on one factor was applied. Ninety-four consecutive patients with low-back pain were randomly assigned to an experimental group having a combined medical and cognitive-behavioral treatment, or to a control group with medical treatment only. Assessments were taken pre-treatment, post-treatment, and - in the treated group only - at a 6-months follow-up. At each assessment, patients kept a pain diary over a period of 4 weeks, and filled in self-report questionnaires. The sample consisted of 36 experimental and 40 control subjects at post-treatment. Experimental subjects reported less pain, better control over pain, more pleasurable activities and feelings, less avoidance and less catastrophizing. In addition, disability was reduced in terms of social roles, physical functions and mental performance. The results were maintained at follow-up. Patients who only received medical treatment showed little improvement. Data indicate that the program meets the needs of the patients and should be continued. (C) 1997 Elsevier Science Ireland Ltd.