Thus far, most systematic reviews commissioned to inform international development policy have focused on questions of ‘what works’, drawing on experimental and quasi-experimental studies of the effects of interventions. This article argues that systematic review methods can be applied to answer a range of different questions for international development and pays particular attention to methods of synthesising qualitative evidence that apply the key principles of systematic reviewing of being comprehensive, systematic and transparent. The article introduces readers to the types of questions for which reviews of qualitative evidence might be appropriate, the types of evidence such reviews might include and the range of methods available for their synthesis.