The Manitoba Longitudinal Study on Aging (MLSA) includes a representative sample (n = 4709) of the residents of Manitoba and combines their responses to a needs assessment interview with complete information on mortality and use of health services (medical, hospital and long-term care) for the years 1970 through 1977 to form a longitudinal record for each participant. This paper describes the MLSA and discusses its relative potential for investigating the health and health care use behaviors of older persons.