Over the last 30 years, oil spills have contributed significantly to coastal and marine pollution, causing disturbance of the coastal environment. This recurrent hazard has increasingly been taken into account through prevention plans in Coastal Zones Integrated Management. Numerous studies have attempted to analyse the effects of oil pollution, in particular to identify those areas that are the most vulnerable. Although several studies have considered both environmental and socioeconomic issues, most of them have focused only on environmental vulnerability. The aim of our research is to formalise an alternative approach to map global vulnerability, using both environmental and socioeconomic factors. This article describes and discusses the methodology used to identify the critical variables required to assess coastal vulnerability to oil spills. The first part introduces previous research and identifies the parameters that have been used to map this type of vulnerability. The study area is presented in the second part of the paper. The third part presents the method we used to compute a spatialised vulnerability index that is based on a multicriteria analysis including both environmental and socioeconomic parameters. The final part of this paper describes and discusses the results of the implementation of this method on Noirmoutier Island located off the west coast of France. The resulting synthetic mapping for risk monitoring, carried out using a geographical information system, seems to be a relevant and useful complementary tool to improve the management of oil spill crises.