The present diary study examined everyday prospective memory tasks in younger and old adults and explored the role of personal task importance, use of reminders and everyday stress as possible correlates of age-related prospective memory performance in everyday life. Results revealed an age benefit in everyday prospective memory tasks. In addition, task importance was identified as a critical moderator of age-related prospective memory performance. More frequent use of reminders and lower levels of stress, however, were associated with better prospective memory performance in general but did not contribute to age-related prospective memory performance. Exploring further possible correlates of prospective memory revealed that the strategy to reprioritize initially planned intentions was associated with age benefits in everyday prospective memory. Results suggest that the age-related benefit observed in experimenter-given tasks transfers to everyday prospective memory and varies in dependence of motivational and cognitive factors. Implications for theoretical models of prospective memory and aging are discussed.