This paper provides a snapshot of the key findings of an Organisation for Economic Co-operation and Development (OECD) review of flood risk prevention policies in the Paris metropolitan area. With an innovative flood risk assessment, the study shows that a major flooding of the Seine River, similar to the flood disaster of 1910, could affect up to 5 million residents in the greater Paris area and cause up to 30 billion (109) euros worth of damage. Economic growth, jobs and public finances could also be significantly affected at the national level. The OECD Review on Flood Risk Management of the Seine River – commissioned by the basin organisation Seine Grands Lacs with the French Ministry of Ecology and Île-de-France regional council – recommends raising risk awareness among citizens and businesses, and improving the resilience of the metropolitan area to flood risks. Recent floods in Europe and New York City's Hurricane Sandy disaster in 2012 illustrated the vulnerability of today's ever-denser cities to flooding and the need to adapt critical infrastructure systems to be able to cope with extreme weather events. The OECD review suggests ways to minimise the risks and better prepare the Île-de-France region. It notes that proposed projects to develop and expand the city's transport and logistics networks offer an opportunity to put some of its suggestions into practice.