This study proposes ways of enhancing whistleblower protection through the review process for the UN Convention against Corruption (UNCAC). It is intended as a contribution to discussions in the UNCAC Implementation Review Group (IRG) and Conference of States Parties (COSP). It surveys the findings in country reviews and thematic reports produced in the first three years of the UNCAC review process. It also reviews information on practice and developments in whistleblower protection and makes recommendations for ways of making further progress. It is based on desk research as well as inputs from member organisations of the UNCAC Coalition. A key focus of this study is on findings about country implementation of UNCAC Article 33.