BACKGROUND: Recent studies on chronic low back pain (cLBP) rehabilitation suggest that predictors of treatment outcome may be differ according to the considered conservative treatment. AIM: To identify predictors of response to back school (BS), individual physiotherapy (IP) or spinal manipulation (SM) for cLBP. POPULATION:outpatients with cLBP. SETTING:Outpatient rehabilitation department. DESIGN: Retrospective analysis from a randomized trial. METHODS: Two hundred and ten patients with cLBP were randomly assigned to either BS, IP or SM; the Roland Morris Disability Questionnaire (RM) was assessed before and after treatment: those who decreased their RM score