Question This review compares mindfulness-based stress reduction (MBSR) to cognitive-behavioural therapy (CBT) in its ability to improve physical functioning and reduce pain intensity and distress in patients with chronic pain (CP), when evaluated against control conditions. Study selection and analysis Ovid MEDLINE, EmbaseClassic+Embase, PsycINFO and the Cochrane Library were searched to identify randomised controlled trials. The primary outcome measure was physical functioning. Secondary outcomes were pain intensity and depression symptoms. We used random and fixed effects (RE and FE) network meta-analyses (NMA) to compare MBSR, CBT and control interventions on the standardised mean difference scale. Findings Twenty-one studies were included: 13 CBT vs control (n=1095), 7 MBSR vs control (n=545) and 1 MBSR vs CBT vs control (n=341). Of the 21 articles, 12 were determined to be of fair or good quality. Findings from RE NMA for change in physical functioning, pain intensity and depression revealed clinically important advantages relative to control for MBSR and CBT, but no evidence of an important difference between MBSR and CBT was found. Conclusions This review suggests that MBSR offers another potentially helpful intervention for CP management. Additional research using consistent measures is required to guide decisions about providing CBT or MBSR. Bac kground Chronic pain (CP) affects one in five adults and may impact all dimensions of a person’s well-being.1 The prevailing psychological intervention for CP is cognitive-behavioural therapy (CBT).2 3 CBT focuses on increasing flexibility in thoughts and behaviours to respond more adaptively to challenges. In the context of CP, CBT often includes psychoeducation about pain, cognitive restructuring of maladaptive pain-related beliefs, problem-solving, relaxation training, behavioural activation and pacing.2 3 Another promising intervention for CP is mindfulness-based stress reduction (MBSR). MBSR is a groupbased intervention that focuses on building awareness and acceptance of moment-to-moment experiences, including physical discomfort and difficult emotions.4 Core components of MBSR include increasing awareness of one’s body, emotions, sensations, thoughts as well as learning self-regulation strategies and more adaptive responses to stress. This systematic review of randomised controlled trials was performed to assess the efficacy of MBSR compared with CBT for CP and pain-related symptoms in adults. At the time of protocol development,5 we anticipated that there would be few head-to-head trials comparing these therapies. We therefore planned to use network meta-analysis (NMA) methods6 7 to inform an indirect comparison between interventions, considering standard care (SC) as the most commonly used control group. Efficacy was assessed based on criteria described in the Initiatives on Methods, and Pain Assessment in Clinical Trials (IMMPACT) recommendations.