Prospective memory (PM) involves remembering intended actions in the future, such as posting a letter when seeing a post box (event-based PM) or making a phone call at 2:00 pm (time-based PM). Studies on aging and PM have often reported negative age e ects in the laboratory, but positive age e ects in naturalistic tasks outside the laboratory (the so-called age–PM-paradox). The present study re-examined this pattern of the paradox by studying, for the rst time, age di erences in time- and event-based PM in lab-based, experimenter-generated naturalistic and self-assigned real-life PM tasks within the same sample of young and older adults. Results showed that di erential age e ects in and outside the laboratory were quali ed by the type of PM cue. While age-related de cits were obtained for laboratory event-based tasks, no age e ect was obtained for naturalistic event-based PM. Age bene ts in the eld were only observed for naturalistic time-based tasks, but not for participants’ own self-assigned time-based tasks. These ndings indicate that the age bene ts for naturalistic PM tasks may have been overestimated due to the dominant use of experimenter-generated naturalistic time-based PM tasks in previous studies. Therefore, the precise pattern of the age–PM-paradox may need rede ning as mostly consisting of negative age e ects in lab-based PM tasks and mostly the absence of negative age e ects (rather than age bene ts) in naturalistic and self-assigned tasks outside the laboratory.