Concerns about expert advice to governments in decision-making on risk prevail in both the European Union (EU) and the United States (US). In the EU, trust in government decisions and expert advice has been undermined by a series of recent food scares, the most significant of which concerns Bovine Spongiform Encephalopathy (BSE). A consequence of the food scares is criticism and distrust of any government decisions on risk, particularly in openly value-laden contexts such as decision-making on genetically modified crops. In the US, distrust in expert advice is in a sense more routine, with political actors regularly resorting to litigation as a means of challenging governmental decisions that adversely affect them. This report compares the changes in the procedures for use of expert advice in decision-making in the EU and in the US in the recent past by researching official documents and the published literature pertaining to two cases: the setting of ambient air quality standards and the regulation of genetically modified crops. Analytic perspectives are drawn from the fields of law, comparative policy studies, and science and technology studies (STS).