This paper explores the exchange relationship between older conservation volunteers (aged over 50 years) and paid group organisers. Using qualitative interview data from seventeen adult volunteers and four organisers recruited from three conservation groups in the North West of England we argue that the psychological contract is important for understanding how organisations can manage and retain volunteers. Our findings highlight the importance of the psychological contract between volunteers and the group organiser, with each party recognising the mutual benefits they bring to the relationship. Participants’ accounts revealed that they chose to take on the often physically challenging conservation work because the natural environment was important to them, but also because there was no obligation for them to attend. Thus, being a conservation volunteer allowed them to retain control over their voluntary time commitment and avoid the pressures of responsibility associated with having people depending upon them. At the micro-level, organisers appreciated the expectations and abilities of individual volunteers, managing and adjusting their own practices accordingly to encourage volunteer retention. We consider the implications of our research in terms of both volunteer and psychological contract theory and discuss the potential implications for organisations in terms of managing and retaining older volunteers.