OBJECTIVES: Prosociality, defined as positive other-regarding intentions and behaviors, is a modifiable factor demonstrated to be associated with better mental, physical, and cognitive health in older adults. Prior studies have largely focused on individual prosocial behaviors, especially volunteering. This study examines whether prosocial intentions are associated with maintaining cognitive health over time. METHODS: Data are from 7,844 adults aged 50 or older in the English Longitudinal Study of Ageing. A 9-item prosocial intentions scale was derived from self-reported items assessing altruism and collectivism. Cognitive health was assessed via biennial completion of tasks related to executive function and verbal memory and incident dementia diagnosis over 11 years. Linear mixed-effects models examined relationships between prosocial intentions and changes in executive function and verbal memory. Cox proportional hazards models assessed risk of developing dementia. A broad array of demographic, socioeconomic, and health-related covariates were also considered. RESULTS: Results from mixed-effects analyses suggest higher prosocial intentions are associated with better cognitive health maintenance after controlling for sociodemographics and baseline health characteristics including depressive symptoms. Participants with high versus low prosocial intentions had 24% slower decline in verbal memory and 55% slower decline in executive function. Similarly, higher prosocial intentions were associated with a 35% reduced hazard of dementia during this same period in fully adjusted models. DISCUSSION: These results suggest aspects of prosociality beyond formal volunteering facilitate maintaining cognitive health among older adults and may provide novel targets for future interventions to enhance healthy aging.