Older adults have much more leisure time today than they have had in the past. Evidence points to the connection between engagement in physical exercise, a leisure time activity, and the overall health of older adults. Because health is an important issue, especially as we age, it is helpful to know that we have some control over it as we age. Cognition, i.e., our ability to remember, to pay attention, and to think, is also a concern in aging. Is it possible that the choices we make about leisure time activities may influence our cognitive abilities in old age? This critical review of the literature examines the effect of three leisure time activities - socializing, physical exercise, and mental exercise - on cognition in older adults.