<p>Participating in satisfying leisure activities is associated with better cognition, while those who do not engage in such activities are at higher risk for cognitive decline. However, little attention has been given to the specific group of non-participants, particularly in terms of how satisfaction or dissatisfaction with not participating is associated with their cognition. Moreover, the cognitive benefits of alternative social roles for this group, such as providing grandchild care, remain unknown. This study aims to assess the association between satisfaction or dissatisfaction with the lack of participation in leisure activities and cognitive function and explore how grandchild care moderates this relationship. We analysed data from 8,109 Europeans aged 50 + from the ninth wave of the Survey of Health Ageing and Retirement in Europe (SHARE). Linear Mixed-Effects Models show that being satisfied with the lack of participation in leisure activities and providing grandchild care are independently associated with better cognitive function. As the frequency of grandchild care increases, cognition improves for both satisfied and dissatisfied non-participants, but this improvement is more pronounced for those who are satisfied. Specifically, cognition scores are highest among satisfied non-participants who provide near-daily grandchild care and lowest among dissatisfied non-participants who do not engage in grandchild care. Our findings emphasize the role of satisfaction and alternative social roles in supporting cognitive health, providing insights for public policy and future research.</p>