Third of a series of surveys relating to Québec residents' health and wellbeing, the Enquête sociale et de santé 1998 falls under the extension survey from Santé Québec 1987 and the Enquête sociale et de santé 1992-1993 which it took over the themes and measures, in order to monitor health and wellbeing conditions and associated risk factors. It was also given the characteristic to tackle several new subjects and to persue aspects dealt with in former surveys. In addition to providing invaluable information on Québec people's physical and mental health problems, it also provides information on their lifestyles and their use of health and social services. The results also take into account the links between various living and health environments (family, social surrounding, working environment, etc). The report is based on data collected during 1998 while visiting and interviewing 12 000 households; it provides information on 30 000 Québec residents, living in all regions of the province. Lastly, this report proposes topics for reflexion concerning action plans.