AIMS:To examine whether the work-life interface (through work-family conflict and overall work-life balance) moderates the relationship between work ability and workplace demands and resources. DESIGN:This study used a cross-sectional survey design to collect data from 426 employees working in residential aged care. METHODS:A paper-based questionnaire was distributed to all permanent and casual employees at eight aged care facilities in Melbourne, Australia, between June - September 2013. Moderation analyses were conducted using PROCESS v. 2.13 in SPSS v. 22. RESULTS/FINDINGS:As expected, workplace demands and resources directly influenced workers' work ability. In addition, moderate-to-high levels of work-family conflict and low-to-moderate levels of satisfaction with work-life balance combined interactively with particular workplace demands and resources (relationships with management, physical demands, and safety climate) to reduce work ability. CONCLUSIONS:This study advances understanding of how work-life balance and work-life conflict can influence work ability levels and shows that addressing the work-life interface may be a legitimate means to improve work ability, potentially leading to continued workforce participation. IMPACT:Staff retention in the residential aged care sector needs to be addressed. One possible means of achieving this is through improving work ability. This study expanded knowledge of how the work-life interface may influence work ability. The research demonstrated that relationships between work ability and particular workplace demands and resources were moderated by the work-life interface. This finding has implications for how human resources managers of residential aged care facilities may improve workforce retention-through facilitating employees to manage the work-life interface better.