Background and purpose High levels of social security benefits in lieu of wages have been suggested as a possible cause of poor outcome from vocational rehabilitation programmes for chronic low back pain. Patient groups have also criticised the assessment procedures used for qualification for such benefits. We conducted a prospective research project to compare the presenting characteristics and outcome from treatment in two groups of unemployed benefit recipients reporting chronic low back pain, one in receipt of a medically determined benefit, incapacity benefit, and a second in receipt of a non-medical benefit, job seekers allowance. Methods Subjects were Employment Services referrals to a rehabilitation programme for people with chronic low back pain. Comparisons were made of the presenting characteristic of each of the two groups at the start of the programme. The subjects were followed up 6 months after a 6-week occupationally orientated rehabilitation programme, the primary outcome measure was working status. Results Incapacity benefit recipients were younger and more likely to report a traumatic onset of pain, be on opioid medication, have had surgery, or been medically dismissed from work, and had received more previous treatment (all P<0.035 values). There were no significant differences in disability, pain report, physical performance, fear avoidance beliefs or psychological distress. At 6 months follow-up there were no significant differences for employment outcome (chi-squared 1.57, P=0.264) or positive progress (chi-squared 1.15, P=0.361). Conclusions Previous and current treatment and mode of onset defined the groups better than disability and pain. This demonstrates that the type of benefit received may be multiply determined. The possible reasons for this are discussed. Both groups were equally likely to return to work or make positive progress. This demonstrates that in this group, attending an occupational programme, benefit type need not be a barrier to successful outcome.