This Topic Guide provides a synthesis of findings from eight international studies of Strategic Environmental Assessments (SEAs), primarily written over the past decade. These studies are based on reviews of over 100 SEAs. In addition, a small number of Strategic Environmental Assessment Terms of Reference (SEA ToR) and related SEA reports, as well as other SEA reports and synthesis studies, were provided by DFID and development partners working with the OECD-DAC task team on SEA. In response to the request to the OECD-DAC task team, follow-up interviews were undertaken with 3 specialists involved in commissioning SEA studies to discuss the findings.