Longitudinal associations between generalized control beliefs (one's perceived capacity to influence events) and cognitive test performance were examined in a population-based sample of young, midlife and older adults. Participants provided measures of perceived control, self-assessed health, education and depression and anxiety symptoms, and completed cognitive tests at two assessments, 4 years apart. For each age group, baseline (between-person) control was positively related to performance on tests of memory (immediate recall and digits backwards), speed (Symbol Digit Modalities Test and choice reaction time) and verbal intelligence (Spot-the-Word). Interaction effects indicated stronger associations of between-person control beliefs with indices of speed for the older age group relative to the younger groups. Within-person changes in control were not significantly associated with changes in cognitive test performance over the study interval. Implications of the findings for self-efficacy based interventions designed to promote cognitive functioning are discussed.