Disasters pose a major public health challenge, as they can have direct and indirect consequences for the health of populations and, consequently, impact health systems. After a disaster, government and relief organizations must identify the priorities needed to guide their actions in order to limit the short- and long-term health consequences. Health risk assessment and epidemiology can be useful tools for gathering information for this task. Through case studies of three European countries (France, the Netherlands, and the United Kingdom), this study describes and compares how these countries have applied epidemiological methods in post-disaster management. The methodology was primarily based on a literature review and direct exchanges via email, telephone, and videoconference. The results show that despite differences in management approaches, similar structures and methods were implemented in all three cases, and that epidemiology teams faced similar key challenges, such as the importance of obtaining adequate and timely environmental samples, how best to take into account the perspectives and needs of the affected populations, the difficulty of identifying and enrolling a significant proportion of the population in the studies, and how and where to find reference levels for comparison, among others. The identification of these specific challenges has enabled the French Institute for Public Health Surveillance (InVS) to strengthen its existing ties with the Dutch National Institute for Public Health and the Environment (RIVM) and the Health Protection Agency (HPA) in the UK. Future meetings are planned to continue this exchange process and develop future collaborations to improve health impact assessment following a disaster in France and the other countries. (R.A.)