Four experiments were conducted that directly compared activity-based to event-based prospective memory. In general, when a goal is established to perform an activity at the conclusion of a different activity, successful completion suffers as compared with associating the same intention with a concrete environmental event. In this regard, activity-based performance was worse than comparable event-based conditions. However, certain conditions such as making transitional points salient between tasks and providing practice may ameliorate these differences between the two kinds of intentions. Other variables that may discriminate between these two kinds of intentions are considered; but the initial evidence favours the notion that ultimate goal completion covaries with the type of intention that is established initially at encoding and the degree of environmental support provided at retrieval. Copyright © 2010 John Wiley & Sons, Ltd.