Many countries have introduced systems of asset declarations for public officials in order to prevent corruption. These systems vary greatly from country to country and their impact on mitigating corruption is not well known. This study provides a systematic analysis of existing practices in asset declaration in Eastern Europe and Central Asia and in some OECD countries in Western Europe and North America. It examines (1) the key elements of asset declaration systems, such as policy objectives, legal frameworks and institutional arrangements; (2) the categories of public officials who are required to submit declarations, and the types of information required; and (3) procedures for verifying information declared, sanctions for violations, and public disclosure. The study also discusses the cost-effectiveness and overall usefulness of declaration systems. It includes case studies of Lithuania, Romania, Spain and Ukraine, and a large number of additional country examples and references.The study presents policy recommendations on the key elements of asset declaration systems. These recommendations will be useful for national governments and international organisations engaged in development, reform and assessment of asset declarations systems at country level.