Ageing of the population is likely to threaten the ability of states to finance welfare states and social protection systems in the future. A viable solution is to increase employment rates and to lengthen working life. To achieve this dual goal requires devising new solutions for working conditions and career paths that help workers to retain their physical and mental health, motivation and productivity over an extended working life. In other words, work must be made sustainable over the life course. Identifying and analysing the factors and actions underpinning sustainable work throughout working life is a research priority for Eurofound in the 2013–2016 programming period. This paper sets out to clarify and illuminate Eurofound’s framework for understanding the rather expansive concept of sustainable work. It can be used as a reference point for a range of Eurofound research projects that examine different aspects of sustainable work.