Globalization of trade, marketing and investment has important implications for public health, both negative and positive. This article considers the implications of the single package of World Trade Organization (WTO) agreements for public health research and policy, focusing on three themes: commodities, intellectual property rights, and health services. The main aims of the analysis are as follows: to identify how trade issues are associated with the transnationalization of health risks and possible benefits; to identify key areas of research; and to suggest policy-relevant advice and interventions on trade and health issues. The next wave of international trade law will need to take more account of global public health issues. However, to become more engaged in global trade debates, the public health community must gain an understanding of the health effects of global trade agreements. It must also ensure that its own facts are correct, so that public health is not blindly used for political ends, such as justifying unwarranted economic protectionism. "Healthy trade" policies, based on firm empirical evidence and designed to improve health status, are an important step towards reaching a more sustainable form of trade liberalization.