The relationship between work and health is a growing concern for employers, policymakers, and social partners alike. Over the past several years, a wealth of research and surveys has begun to shed significant light on the complex interplay between these two major areas. We naturally refer to the Working Conditions Surveys conducted by the European Foundation for the Improvement of Living and Working Conditions and to the French surveys carried out by the Directorate for Research, Studies, and Statistics (DARES), as well as to the 2003 SUMER survey on medical surveillance of occupational risks, the Decennial Survey (INSEE), the Aging, Health, and Work (VISAT), the ESTEV survey, the Health and Professional Life After Age 50 (SVP 50) survey, the survey of the EDF-GDF employee cohort (Gazel survey), as well as the various surveys produced by the social partners. However, in the general population, surveys remain limited; the areas explored mainly concern the epidemiology of working conditions and exposure to occupational risks. The approach to the links between working conditions and health determinants remains fragmented. Until now, in the various Health Barometers, the study of health determinants has been limited mainly to the effects of sociodemographic and socioeconomic characteristics. The 2005 Health Barometer offers, for the first time, due to the size of its sample, the opportunity for an analysis of a large sample of working-age individuals representative of the French population. In this context, in collaboration with Dares, certain variables related to working conditions and a few additional questions were introduced to broaden the scope of the inquiries and analyses. This chapter aims to examine, from a cross-sectional perspective, the links between occupational activity, working conditions, and health behaviors among the working-age population aged 16–65. In particular, it explores the “protective” and/or harmful effects of work by examining the links between these variables and various health indicators. [chapter excerpt]