Background. Few data are available on the course of and predictors for disability in patients with chronic nonspecific low back pain (CNSLBP). Objective. The purpose of this study was to describe the course of disability and identify clinically important prognostic factors of low-back-pain-specific disability in patients with CNSLBP receiving multidisciplinary therapy. Design. A prospective cohort study was conducted. Methods. A total of 1,760 patients with CNSLBP who received multidisciplinary therapy were evaluated for their course of disability and prognostic factors at baseline and at 2-, 5-, and 12-month follow-ups. Recovery was defined as 30% reduction in low back pain-specific disability at follow-up compared with baseline and as absolute recovery if the score on the Quebec Back Pain Disability Scale (QBPDS) was <= 20 points at follow-up. Potential prognostic factors were identified using multivariable Results. Mean patient-reported disability scores on the QBPDS ranged from 51.7 (SD=15.6) at baseline to 31.7 (SD=15.2), 31.1 (SD=18.2), and 29.1 (SD=20.0) at 2, 5, and 12 months, respectively. The prognostic factors identified for recovery at 5 and 12 months were younger age and high scores on disability and on the 36-Item Short-Form Health Survey (SF-36) (Physical and Mental Component Summaries) at baseline. In addition, at 5-month follow-up, a shorter duration of complaints was a positive pred Limitations. Missing values at 5- and 12-month follow-ups were 11.1% and 45.2%, respectively. Conclusion. After multidisciplinary treatment, the course of disability in patients with CNSLBP continued to decline over a 12-month period. At 5- and 12-month follow-ups, prognostic factors were identified for a clinically relevant decrease in disability scores on the QBPDS.