This study investigated age-related differences in intentional forgetting (IF) of prospective memory (memory for actions to be performed in the future) in young (19-30 years) and late-midlife adults (LMA; 57-75 years). Prospective memory (PM) performance was examined by using the Virtual Week (VW) Task. An IF procedure was embedded into the VW task and the participants were instructed to forget some of the PM tasks that they were to remember and execute later on a virtual day. The study compared performances of the young and the LMA participants in the context of event- or time-based regular and irregular tasks. The results confirmed previous findings in showing that LMA participants exhibited worse PM than younger participants in lab-based tasks. In addition, although PM and IF performances separately have been shown to be affected by cognitive aging, larger age-related differences were not found in PM performance under IF conditions.