Patients with a degenerative lumbar disorder selected for spinal fusion surgery by an experienced orthopaedic surgeon, were invited to participate in an exercise and behavioural modification programme. The goal was to let the patients experience that it is safe to move. 50 patients; mean age 49 years (19-76 years), mean duration of complaints ten years (2-39 years), agreed to participate. 26 patients had undergone back surgery. 80% were on sick leave or disability pension; 85% had either previously diagnosed psychiatric disorder or high scores for somatization or abnormal illness behaviour. At follow-up, 21 (42%) patients wanted surgery, 8 (16%) were uncertain, and 18 (36%) did not want surgery, 17 patients reported improved main symptoms, 18 were unchanged, and 12 had deteriorated. Previous surgery, illness behaviour and weak trunk muscles were associated with poor improvement and desire for surgery. Age, gender, emotional distress, intensity of pain, neurological or radiological signs or the number of exercise sessions taken did not influence results.