The National Longitudinal Mortality Study (NLMS) consists of a database developed for the purpose of studying the effects of demographic and socio-economic characteristics on differentials in U.S. mortality rates. The NLMS is a unique research database in that it is based on a random sample of the non-institutionalized population of the United States. It consists of U.S. Census Bureau data from Current Population Surveys, Annual Social and Economic Supplements and a subset of the 1980 Census combined with death certificate information to identify mortality status and cause of death. The study currently consists of approximately 3.6 million records with over 250,000 identified mortality cases. The content of the socio-economic variables available offers researchers the potential to answer questions on mortality differentials for a variety of important socio-economic and demographic subgroups not covered as extensively in other databases. This project has generated over 70 publications in various prominent scholarly, scientific and public health related journals.