AbstractThe higher performance of older people in prospective memory (PM) tasks in a naturalistic setting rather than in a laboratory setting is well known in cognitive aging research and is called the “age prospective memory paradox”. The mechanism of the paradox is poorly understood. To clarify this complex phenomenon, testing of the contribution of candidate variables that may influence PM performance in older adults is needed. To identify possible variables, this study used the Prospective and Retrospective Memory Questionnaire (PRMQ; Smith, Della Sala, Logie, & Maylor, 2000) which was developed to evaluate PM and retrospective memory (RM) failure in daily life. In this large‐sample survey study (n = 2610) we verified the reliability and validity of the Japanese version of the PRMQ in young (n = 459), young‐old (n = 1291) and old‐old (n = 860) people. First, we found high reliability for both the PM and RM dimensions of the PRMQ in all age groups. Second, the validity was confirmed not by the simple score on PM items but with a subtraction score (PM score minus RM score). In addition, our results also provide knowledge of how personality and lifestyle relate to self‐rated memory failures.