Objectives: To compare the effectiveness of corticosteroid injections with physiotherapeutic interventions for the treatment of lateral epicondylitis (tennis elbow). Data sources: The electronic databases AMED, Cinahl, Medline and Embase were searched up to Week 12 2009. In addition, the Cochrane Central Register of Controlled Clinical Trials, the Metaregister of Controlled Clinical Trials and the Physiotherapy Evidence Database (PEDro) were searched up to March 2009. Review methods: All English-language randomised controlled trials (RCTs) that included participants with a clinical diagnosis of lateral epicondylitis, comparing corticosteroid injections with physiotherapeutic interventions, and used at least one clinically relevant outcome measure were included. The review authors extracted and analysed the data independently, using the PEDro scale to assess the methodological quality of each eligible study. Results: Five RCTs were identified and included in the review. Four of the studies included the measurement of pain-free grip strength. Standardised mean differences (effect sizes) were calculated for this outcome measure and assessor's rating of severity at 3, 6, 12, 26 and 52 weeks for two of the RCTs. Large effect sizes were demonstrated in favour of corticosteroid injections at short-term follow-up. At intermediate- and long-term follow-up, medium-to-large effect sizes were demonstrated in favour of physiotherapeutic interventions compared with corticosteroid injections. However, at long-term follow-up, the research suggests that there is a small benefit of physiotherapeutic interventions compared with a 'wait and see' policy. Conclusion: Overall, the findings indicated that corticosteroid injections are effective at short-term follow-up, and physiotherapeutic interventions are effective at intermediate- and long-term follow-up. However, due to the limited number of high-quality RCTs and differences in the interventions and outcomes utilised within each of the included studies, any conclusions drawn must be interpreted with caution.