The article begins with an examination of the concept of trust. Following the work of Niklas Luhmann, we argue that the main role of trust is to reduce the complexity of the events and situations with which an individual is confronted. We then turn our attention to the factors that have the greatest influence on the level of trust that residents place in managers of regional risk. The author’s research into the risks related to both coastal flooding and sites of hazardous material storage regulated by the European Union’s Seveso Directives has allowed three main factors to be identified. First, residents of areas subjected to these risks tend to put more trust in the people and institutions that are geographically and institutionally closest to them. Next, the degree of credibility accorded to managers depends on an appraisal of their competence. The third criterion is ethical. Residents place more trust in entities that put their safety first and cannot be suspected of being motivated by other goals, such as economic profitability. Thus, in order for information provided by public officials and other risk managers to be considered credible, these actors must be seen as possessing these three qualities.