To study the epidemiology of rural populations in the context of contemporary issues in public health, a population laboratory (Health Census '89) was established in Otsego County, New York, by the Research Institute of the M.I. Bassett Hospital, affiliated with the Columbia University School of Public Health. Such a laboratory is needed because of an apparent lag in positive health indices in rural populations across the United States, resulting in rates of chronic diseases, such as coronary heart disease, for which rural areas now exceed urban ones. This was confirmed for Otsego County by the survey Health Census '89, the foundation of a rural population laboratory, in which all residents were enumerated and characterized as to their prevalent diseases, health behaviors, use of preventive services, and environmental exposures. Heart disease, cancer, and diabetes mellitus rates were found to exceed average rates for US urban areas, while the data on preventive health behaviors suggest this is a population of “late adopters.” The survey, conducted in 1989, had an 86.6% response rate, and enumerated 17,147 households and 44,406 persons. The authors discuss adults aged 17–64 years, 58 percent of the total census (n = 25,614). Sharp gradients in disease prevalence, risk factors, and utilization of preventive services were observed across educational strata. Data from Health Census '89 were used as the basis for a successful community intervention program, which targeted identified high risk groups. Rural populations are excellent settings for community interventions, offering laboratories where new strategies of risk reduction and provision of preventive services might be tested. Am J Epidemiol 1998; 148:949–57.