Background: Opioids are frequently used for the postoperative treatment of chronic disabling occupational musculoskeletal disorders. In many such cases, long-termopioid use persists because of patient requests for ongoing pain relief. Little is known about the relationship between chronic opioid use and functional recovery in these patients. Methods: A total of 1226 patients with a chronic disabling occupational musculoskeletal disorder were consecutively admitted into an interdisciplinary functional restoration program. They were divided into two groups: 630 patients who reported no opioid use at the time of admission (No group) and 596 patients who reported some opioid use at the time of admission (Yes group). The 516 patients for whom daily opioid doses could be determined were further divided into four subgroups: Low (<30 mg, n = 267), Medium (31 to 60 mg, n = 112), High (61 to 120 mg, n = 78), and Very High (>120 mg, n = 59). During the initial weeks of treatment, patients consented to be weaned from all opioid medications. In addition, the patients were assessed before and after rehabilitation with regard to self-reported measures of pain, function, and depression and were analyzed for change. One year after the termination of treatment, socioeconomic outcomes were assessed to measure work and financial status, healthcare utilization, and recurrent injury-associated pain. Results: A higher post-injury opioid dose was associated with a greater risk of program noncompletion, which was anticipated because of the requirement that patients taper opioids. High opioid use was significantly related to important socioeconomic outcomes, such as lower rates of return to work and work retention as well as higher healthcare utilization (p ≤ 0.05 for all). Moreover, at one year after treatment, the group reporting the highest opioid use was 11.6 times as likely to be receiving Social Security Disability Income/Supplemental Security Income as compared with the group reporting no opioid use at the time of admission into the program. Conclusions: Chronic opioid use beginning after awork-related injury is a predictor of less successful outcomes for patients whose final treatment intervention is an interdisciplinary functional restoration program. Higher dose levels are associated with progressively greater indemnity and medical costs for ongoing disability. Physicians involved in the treatment of chronic disabling occupational musculoskeletal disorders should be aware of problems associated with permitting long-term opioid use in patients with a disabling occupational disorder. Level of Evidence: Prognostic Level I. See Instructions to Authors for a complete description of levels of evidence.