A key neuro-cognitive function that promotes autonomy and everyday functioning in old age is prospective memory (PM), defined as the capacity to remember to carry out intentions in the future. This study aimed at understanding if non-cognitive factors of metacognition and motivation are related to event-based and time-based laboratory PM, as well as to naturalistic PM in older adults, above and beyond the influences of neuropsychological determinants. We applied regression analyses predicting individual differences in classical PM tasks, in a sample of 99 healthy older participants (aged 64–88 years). Results indicated that metacognition, measured as memory self-efficacy and perceived competence in cognitive tasks, was related to laboratory time-based PM. Consistency of interests, a motivational factor, was associated with naturalistic PM. None of the non-cognitive factors related to event-based PM. Our study underlines the importance of considering non-cognitive characteristics when evaluating PM capacity, a key component of cognitive aging.