Over 70% of people in developed countries develop low back pain (LBP) at some time. But recovery is not always favourable: 82% of non recent-onset patients still experience pain 1 year later. Many patients with chronic LBP who were initially told that their natural history was good spend months or years seeking relief.We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of oral drug treatments? What are the effects of injection therapy? What are the effects of non-drug treatments? What are the effects of non-surgical and surgical treatments? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2009 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).We found 64 systematic reviews or RCTs that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.In this systematic review, we present information relating to the effectiveness and safety of the following interventions: acupuncture, analgesics, antidepressants, back schools, behavioural therapy, electromyographic biofeedback, exercise, injections (epidural corticosteroid injections, facet joint injections, local injections), intensive multidisciplinary treatment programmes, lumbar supports, massage, muscle relaxants, non-steroidal anti-inflammatory drugs (NSAIDs), non-surgical interventional therapies (intradiscal electrothermal therapy, radiofrequency denervation), spinal manipulative therapy, surgery, traction, and transcutaneous electrical nerve stimulation (TENS).