This paper describes the strategy of provision and assessment of preventive health services that the Mexican Institute of Social Security (IMSS) established in 2002 and that for social communication purposes, was called PREVENIMSS. The strategy is composed by five programs: Children's Health, Adolescents' Health, Women's Health, Men's Health and Seniors' Health. The objectives of these programs are the following: to provide a group of actions to promote and protect health, according to their age, sex and risk factors; to incorporate new preventive actions in order to face demographic and epidemiologic transition; to promote the participation of population in health care; to integrate provision of preventive services in family medicine clinics, and to broaden their coverage and impact. The modernization process of the statistical information system is also described in this paper. It included several aspects, such as the establishment of an automated record of preventive actions, which allowed the generation of relevant and timely information to measure the coverage and both national and local impacts.