Background: Many people with low back pain (LBP) become frequent users of healthcare services in their attempt to find treatments that minimise the severity of their symptoms. Back School consists of a therapeutic programme given to groups of people that includes both education and exercise. However, the content of Back School has changed over time and appears to vary widely today. This review is an update of a Cochrane review of randomised controlled trials (RCTs) evaluating the effectiveness of Back School. We split the Cochrane review into two reviews, one focusing on acute and subacute LBP, and one on chronic LBP. Objectives: The objective of this systematic review was to determine the effect of Back School on pain and disability for adults with chronic non-specific LBP; we included adverse events as a secondary outcome. In trials that solely recruited workers, we also examined the effect on work status. Search methods: We searched for trials in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, two other databases and two trials registers to 15 November 2016. We also searched the reference lists of eligible papers and consulted experts in the field of LBP management to identify any potentially relevant studies we may have missed. We placed no limitations on language or date of publication. Selection criteria: We included only RCTs and quasi-RCTs evaluating pain, disability, and/or work status as outcomes. The primary outcomes for this update were pain and disability, and the secondary outcomes were work status and adverse events. Data collection and analysis: Two review authors independently performed the 'Risk of bias' assessment of the included studies using the 'Risk of bias' assessment tool recommended by The Cochrane Collaboration. We summarised the results for the short-, intermediate-, and long-term follow-ups. We evaluated the overall quality of evidence using the GRADE approach. Main results: For the outcome pain, at short-term follow-up, we found very low-quality evidence that Back School is more effective than no treatment (mean difference (MD) -6.10, 95% confidence interval (CI) -10.18 to -2.01). However, we found very low-quality evidence that there is no significant difference between Back School and no treatment at intermediate-term (MD -4.34, 95% CI -14.37 to 5.68) or long-term follow-up (MD -12.16, 95% CI -29.14 to 4.83). There was very low-quality evidence that Back School reduces pain at short-term follow-up compared to medical care (MD -10.16, 95% CI -19.11 to -1.22). Very low-quality evidence showed there to be no significant difference between Back School and medical care at intermediate-term (MD -9.65, 95% CI -22.46 to 3.15) or long-term follow-up (MD -5.71, 95% CI -20.27 to 8.84). We found very low-quality evidence that Back School is no more effective than passive physiotherapy at short-term (MD 1.96, 95% CI -9.51 to 13.43), intermediate-term (MD -16.89, 95% CI -66.56 to 32.79), or long-term follow-up (MD -12.86, 95% CI -61.22 to 35.50). There was very low-quality evidence that Back School is no better than exercise at short- term follow-up (MD -2.06, 95% CI -14.58 to 10.45). There was low-quality evidence that Back School is no better than exercise at intermediate-term (MD -4.46, 95% CI -19.44 to 10.52) and long-term follow-up (MD 4.58, 95% CI -0.20 to 9.36). For the outcome disability, we found very low-quality evidence that Back School is no more effective than no treatment at intermediate-term (MD -5.92, 95% CI -12.08 to 0.23) and long-term follow-up (MD -7.36, 95% CI -22.05 to 7.34); medical care at short-term (MD -1.19, 95% CI -7.02 to 4.64) and long-term follow-up (MD -0.40, 95% CI -7.33 to 6.53); passive physiotherapy at short-term (MD 2.57, 95% CI -15.88 to 21.01) and intermediate-term follow-up (MD 6.88, 95% CI -4.86 to 18.63); and exercise at short-term (MD -1.65, 95% CI -8.66 to 5.37), intermediate-term (MD 1.57, 95% CI -3.86 to 7.00), and long-term follow-up (MD 4.54, 95% CI -4.44 to 13.52). We found very low-quality evidence of a small difference between Back School and no treatment at short-term follow-up (MD -3.38, 95% CI -6.70 to -0.05) and medical care at intermediate-term follow-up (MD -6.34, 95% CI -10.89 to -1.79). Still, at long-term follow-up there was very low-quality evidence that passive physiotherapy is better than Back School (MD 9.60, 95% CI 3.65 to 15.54). Few studies measured adverse effects. The results were reported as means without standard deviations or group size was not reported. Due to this lack of information, we were unable to statistically pool the adverse events data. Work status was not reported. Authors' conclusions: Due to the low- to very low-quality of the evidence for all treatment comparisons, outcomes, and follow-up periods investigated, it is uncertain if Back School is effective for chronic low back pain. Although the quality of the evidence was mostly very low, the results showed no difference or a trivial effect in favour of Back School. There are myriad potential variants on the Back School approach regarding the employment of different exercises and educational methods. While current evidence does not warrant their use, future variants on Back School may have different effects and will need to be studied in future RCTs and reviews.