A brief introduction to gerontological longitudinal research methods and analysis is provided. The gerontological research questions that demand longitudinal study are identified. The use of secondary data analysis is shown to be essential to these studies. These analyses present opportunities to maximize both longitudinal research strategies and research efficiencies. The importance of administrative and financial stability for maintaining data bases for longitudinal research is presented by using examples. A brief overview of major Canadian longitudinal studies of aging and selected studies in other countries is provided. Finally, many sources of both quantitative and qualitative data for longitudinal gerontological studies are identified.