Traumatic brain injury (TBI) patients often present with prospective memory (PM) dysfunction. Forgetting to complete tasks may result in a loss of independence, limited employment prospects and anxiety, therefore, it is important to develop programs to improve PM performance in TBI patients. A strategy which may improve PM performance is implementation intentions. It involves making explicit plans specifying when, where and how one will perform a task in the future. In the present study, a group of 36 TBI patients and a group of 34 controls performed Virtual Week using either implementation intentions or no strategy. The results showed that the PM performance of TBI patients was less accurate than controls, in particular when the PM cue was time-based. No effect of implementation intentions was observed for TBI patients, however, controls improved their PM performance when the task was time-based. The findings suggest that strategies to improve PM in this clinical group are likely to be more complex than those that benefit healthy adults and may involve targeting phases of the PM process other than, or in addition to, the intention formation phase. (JINS, 2015, 21, 305–313)