This study examined relationships between cognitive functioning in older people and (1) levels of mental, physical and social activities, and (2) intentions regarding maintenance of cognitive functioning. Participants (N = 145) were 70-91 years of age, varied in health status and socio-economic backgrounds. Current cognitive functioning was assessed by psychometric tests and real world problem solving tasks. Crystallized ability was indexed by the National Adult Reading Test (NART). Degree of involvement in mentally demanding activities was positively related to a fluid cognitive factor after effects of age, prior functioning, gender, health, and socio-economic status were accounted for. Social and physical activities were not related to the cognitive measures. Age effects on cognitive functioning were reduced among participants who reported undertaking activities intentionally to maintain cognitive functioning. (Contains 10 tables and 1 figure.)