Abstract
Health impact assessment (HIA) seeks to expand evaluation of policy and programmes in all sectors, both private and public, to include their impact on population health. While the idea that the public's health is affected by a broad array of social and economic policies is not new and dates back well over two centuries, what is new is the notion-increasingly adopted by major health institutions, such as the World Health Organisation (WHO) and the United Kingdom National Health Services (NHS)-that health should be an explicit consideration when evaluating all public policies. In this article, it is argued that while HIA has the potential to enhance recognition of societal determinants of health and of intersectoral responsibility for health, its pitfalls warrant critical attention. Greater clarity is required regarding criteria for initiating, conducting, and completing HIA, including rules pertaining to decision making, enforcement, compliance, plus paying for their conduct. Critical debate over the promise, process, and pitfalls of HIA needs to be informed by multiple disciplines and perspectives from diverse people and regions of the world.