What are the risks and opportunities associated with genetically engineered organisms in terms of the environment, food safety, and economic and trade issues? The various and often diverging answers to this question were discussed at the workshop on Challenges and Risks of GMOs - What Risk Analysis is Appropriate? Options for Future Policy Making Towards Integrated Agro-Food Systems, held in Maastricht, Netherlands 16-18 July 2003. Participants represented a diversity of backgrounds, ranging from genetics to social sciences and government, in order to overcome traditional compartmentalisation and arrive at integrated strategies for future policy making. Discussions covered the relevant WTO Agreements and their relationship with other multilateral accords. Regional and national approaches for risk analysis and the relevant intellectual property regimes were also analysed. Speakers' presentations covered the problems for risk assessment stemming from scientific uncertainty, consumers' rights and requirements concerning access to information, and the different positions of relevant stakeholders.