Several recent epidemiological studies have demonstrated that urban air pollution has short-term effects on both mortality and morbidity, even at current ambient pollution levels. These findings called existing standards into question and justified combining epidemiological surveillance with air quality monitoring. The ERPURS project, implemented in the Paris metropolitan area, demonstrated that it was possible to estimate the health impact of air pollution using routinely collected health indicators, particularly mortality and hospital admissions. To assess the relevance and feasibility of extending such a surveillance system to other metropolitan areas, the French Institute for Public Health Surveillance coordinated a multicenter study across eight French metropolitan areas: Bordeaux, Le Havre, Lille, Lyon, Marseille, Rouen, Strasbourg, and Toulouse. Paris joined the study with results from the ERPURS study. The main objective of this project was to assess the feasibility of a multicenter system for the epidemiological surveillance of the short-term health effects of urban air pollution, using mortality indicators in this initial phase.