BACKGROUND: Lateral elbow tendinopathy (LET) is a common complaint causing characteristic pain in the lateral elbow and upper forearm, and tenderness of the forearm extensor muscles. It is thought to be an overuse injury and can have a major impact on the patient's social and professional life. The condition is challenging to treat and prone to recurrent episodes. The average duration of a typical episode ranges from 6 to 24 months, with most (89%) reporting recovery by 1 year. OBJECTIVES: This systematic review aims to summarise the evidence concerning the clinical effectiveness and cost-effectiveness of conservative interventions for LET. DATA SOURCES: A comprehensive search was conducted from database inception to 2012 in a range of databases including MEDLINE, EMBASE and Cochrane Databases. METHODS AND OUTCOMES: We conducted an overview of systematic reviews to summarise the current evidence concerning the clinical effectiveness and a systematic review for the cost-effectiveness of conservative interventions for LET. We identified additional randomised controlled trials (RCTs) that could contribute further evidence to existing systematic reviews. We searched MEDLINE, EMBASE, Allied and Complementary Medicine Database, Cumulative Index to Nursing and Allied Health Literature, Web of Science, The Cochrane Library and other important databases from inception to January 2013. RESULTS: A total of 29 systematic reviews published since 2003 matched our inclusion criteria. These were quality appraised using the Assessment of Multiple Systematic Reviews (AMSTAR) checklist; five were considered high quality and evaluated using a Grading of Recommendations, Assessment, Development and Evaluation approach. A total of 36 RCTs were identified that were not included in a systematic review and 29 RCTs were identified that had only been evaluated in an included systematic review of intermediate/low quality. These were then mapped to existing systematic reviews where further evidence could provide updates. Two economic evaluations were identified. LIMITATIONS: The summary of findings from the review was based only on high-quality evidence (scoring of > 5 AMSTAR). Other limitations were that identified RCTs were not quality appraised and dichotomous outcomes were also not considered. Economic evaluations took effectiveness estimates from trials that had small sample sizes leading to uncertainty surrounding the effect sizes reported. This, in turn, led to uncertainty of the reported cost-effectiveness and, as such, no robust recommendations could be made in this respect. CONCLUSIONS: Clinical effectiveness evidence from the high-quality systematic reviews identified in this overview continues to suggest uncertainty as to the effectiveness of many conservative interventions for the treatment of LET. Although new RCT evidence has been identified with either placebo or active controls, there is uncertainty as to the size of effects reported within them because of the small sample size. Conclusions regarding cost-effectiveness are also unclear. We consider that, although updated or new systematic reviews may also be of value, the primary focus of future work should be on conducting large-scale, good-quality clinical trials using a core set of outcome measures (for defined time points) and appropriate follow-up. Subgroup analysis of existing RCT data may be beneficial to ascertain whether or not certain patient groups are more likely to respond to treatments. STUDY REGISTRATION: This study is registered as PROSPERO CRD42013003593. FUNDING: The National Institute for Health Research Health Technology Assessment programme.