Predicting ongoing disability for chronic non-specific low back pain (LBP) is important to avoid prolonged disability.Determine predictors of disability at 6 month follow-up in patients with LBP at medium risk of ongoing disability.Baseline data was collected from 108 patients with medium-risk chronic non-specific LBP (mean age 50.4 years, SD 13.6) from six private chiropractic and physiotherapy clinics in Australia who took part in a randomised control trial. All patients received a pragmatic course of multimodal physical treatments [e.g., manual therapy (spinal manipulation or mobilization and/or soft tissue massage)] combined with advice, education and exercise. Baseline prognostic variables included sociodemographic, physical and psychological characteristics. Primary outcome was disability (Roland Morris Disability) at 6 month follow-up. Multivariable linear regression analysis was conducted.Variables remaining in the final multivariable model: lower work ability (β = - 1.05, 95% CI - 1.40 to - 0.70; p < 0.0001) and consultation with a medical specialist for back pain in the preceding 3 months (β = 3.35, 95% CI 1.14 to 5.55; p < 0.003), which significantly predicted higher disability at 6 months (unadjusted R  = 0.31). Those with a lower work ability (scale 1 to 10) and who had seen a medical specialist for their back pain were more likely to report greater LBP-related disability at 6 months.Patients with chronic LBP presenting to primary care with lower work ability and recent consultation with a medical specialist for LBP are more likely to have a worse prognosis; these are indicators to clinicians that standard conservative care may not adequately manage the patients' needs.