Purpose: Little is known about the motivation for older workers to work and to remain active in the labor market. Research on age and motivation is limited and, moreover, conceptually diverse. In this study, we address age-related factors that influence the work motivation of older workers. More specifically, we examine how various conceptualizations of the age factor affect the direction and termination of the motivation to continue to work of older workers. Methodology: A literature review of age-related factors and motivation to continue to work. Findings: Results from 24 empirical and 9 conceptual studies indicate that most age-related factors can have a negative impact on the motivation to continue to work of older people. These findings suggest that age-related factors are important in understanding older workers' motivation to continue to work and that further research is needed to more fully understand the underlying processes that govern how these age-related factors influence the motivation to continue to work. Research limitations / implications: Based on the aforementioned findings, we were able to formulate a research agenda for future research, namely: 1) a need for a meta-analysis on age and motivation to determine the actual effect sizes, 2) additional theoretical attention to the underlying age-related processes, 3) more psychometric studies examining the operationalization and measurement of the age-related variables, and 4) additional empirical research on age-related variables and motivation. Practical implications: Age-related factors identified in this study, such as declining health and career plateaus, should be addressed by HRM policies. HRM practices that could motivate older workers to continue to work include ergonomic adjustments and continuous career development. Originality / value of paper: Research on age and motivation is limited and conceptually diverse. This paper is one of the first studies to explore the relations between different conceptualizations of age and motivation.