Systematic reviews are well established in evidence-based medicine, where experimental results are used to support decision making. The methodology is gradually spreading to other subject areas, including the social sciences, with the support of organisations such as the Campbell Collaboration1 and the EPPI Centre2. This paper describes the support provided to systematic reviewers at the London School of Hygiene & Tropical Medicine by Library & Archives Service staff. A systematic review is a specific type of literature review. A clear question is set before comprehensive and transparent methods are used to identify, select and evaluate all of the relevant research. Data is then collected and analysed from each included study to provide unbiased summaries of the results. In this way, reliable evidence-based reviews can be produced and readers can have confidence in the conclusions drawn. The PRISMA Statement (Moher et al., 2009) has been developed to make sure that all relevant methodological information is included in the published review, and can also be used to guide reviewers through the systematic review process. It is useful when helping reviewers as it provides minimum standards for each stage of the review process, including the literature searching and study selection process.