Introduction Prospective memory has received relatively little attention from a clinical perspective, yet it is an important part of daily functioning. Executive functions have been linked with prospective memory abilities, and age differences are found in both executive functions and prospective memory. The purpose of this study was to investigate whether age cohort differences in prospective memory abilities are mediated by executive functions, specifically inhibition.Method Participants (N = 108) consisted of young adults (n= 53) and older adults (n= 55) without any neurocognitive impairment. Participants completed a clinical interview and a battery of neuropsychological tests that included the Mini-Mental Status Exam–2 Standard Version (MMSE-2-SV), the Wisconsin Card Sorting Test-64 (WCST-64), the Delis-Kaplan Executive Functioning System Color-Word Interference Test (D-KEFS CWIT), and the Virtual Kitchen Protocol (VKP).Results Young adults had higher prospective memory scores than older adults. Inhibition (i.e., D-KEFS CWIT) mediated the relationship between age cohort and prospective memory, while cognitive flexibility did not mediate the relationship.Conclusions Older adults may have diminished inhibition abilities that may negatively affect their ability to complete prospective memory tasks.