Most systematic reviews concentrate on pooling effect estimates from multiple trials from different contexts, as though there were one underlying effect that can be uncovered by pooling. They often fail to examine mechanisms and how these might interact with context to generate different outcomes in different settings and populations. Realist reviews do focus on questions of what works for whom under what conditions but do not use rigorous methods to search for, appraise the quality of and synthesise evidence to answer these questions. We show how systematic reviews can explore more nuanced questions informed by realism while retaining rigour. Using the example of a systematic review of school-based interventions to prevent dating and other gender-based violence, we first examine how systematic reviews can define context–mechanism–outcome configurations. This can occur through synthesis of intervention descriptions, theories of change and process evaluations.