The majority of research on metamemory focuses on retrospective memory: memory for past events. Prospective memory, in contrast, refers to the process of remembering to carry out intentions in the future. Despite claims that metacognition is essential to prospective remembering, it is unclear whether the metamemorial effects that researchers have observed in studies of retrospective memory extend to prospective memory. In the present study, we tested whether the underconfidence with practice (UWP) effect, the finding that in multitrial learning situations, participants become relatively underconfident following retrieval practice, would generalize to a prospective memory paradigm. Participants memorized target-response word pairs and were told that during an upcoming lexical-decision task (the ongoing task), the targets would appear and, should they recognize any of these targets, they were to notify the experimenter and attempt to recall the associated response. Participants then predicted their ability to recognize each target and recall each response. Participants predicted their memory and completed the ongoing task three times. In Experiment 1, we observed preliminary evidence for UWP for the prospective component (recognizing the targets) but no UWP for the retrospective component (recalling the responses). However, after changing the way JOLs were elicited to be more consistent with past studies of UWP (i.e., cueing them with the target instead of the target-response word pair), we observed UWP for both prospective and retrospective memory in Experiments 2 and 3. The present results suggest that, as with retrospective memory, participants become relatively underconfident in their prospective memory following practice.