The health impact assessment (HIA) of air pollution in the Clermont-Ferrand metropolitan area is part of the Auvergne Region’s Regional Air Quality Plan (PRQA), which sets out guidelines aimed at preventing, reducing, or mitigating the effects of air pollution. In this study, the short-term health impact of air pollution is calculated in terms of premature mortality and morbidity (hospital admissions). The long-term health impact is estimated by the number of deaths attributable to air pollution. The study area selected corresponds to an urban zone where the population’s exposure to air pollution can be considered homogeneous. It comprises four municipalities: Clermont-Ferrand, Chamalières, Beaumont, and Aubière, representing a total population of 175,938 inhabitants. The study period spans two tropical seasons, from October 1, 1999, to September 30, 2000. This study is based on the urban air pollution EIS methodology proposed by the French Institute for Public Health Surveillance (InVS), which consists of four steps: hazard identification, selection of exposure-risk relationships, exposure estimation, and risk characterization. The pollution indicators selected are based on the five pollutants routinely measured in the area: SO2, NO2, O3, FN, and PM10. The exposure-risk relationships used are derived from epidemiological studies conducted in the general population, with a focus on multicenter and European studies. The short-term health impact of air pollution during the 1999–2000 tropical year amounts to 28 premature deaths, 8 hospital admissions for respiratory causes, 50 hospital admissions for cardiovascular causes in winter, and 24 in summer. The various air pollution reduction scenarios show that the greatest health benefits are achieved with a 25% reduction in average annual pollution levels. The long-term health impact of air pollution amounts to 69 deaths per year. The various air pollution reduction scenarios show that the European standard applicable in 2005 is already being met. Compliance with the European standard scheduled for 2010 should, however, result in a 26% health benefit; a 25% reduction in pollution levels, on the other hand, would result in a 42% health benefit. Given the uncertainties and limitations of the methodology used, the results should be interpreted as orders of magnitude of the impact of air pollution on the health of the population in the study area. However, this study shows that even though the relative risks associated with air pollution are low, the large proportion of people exposed results in a significant collective impact. It also shows that health effects already appear at pollution levels well below those for which management measures are currently taken, and that the most effective actions would therefore be those that combine daily reductions in emissions at the source with a significant decrease in the number of annual pollution peaks.