Younger and older adults were compared in 4 directed forgetting experiments. These varied in the use of categorized versus unrelated word lists and in the use of item by item versus blocked remember-forget cueing procedures. Consistent with L. Hasher and R. T. Zacks's (1988) hypothesis of impaired inhibitory mechanisms in older adults, a variety of findings indicated that this age group is less able than yoimger adults to suppress the processing and retrieval of items designated as to be forgotten (TBF). Specifically, in comparison with younger adults, older adults produced more TBF word intrusions on an immediate recall test (Experiments 1A and 1B), took longer to reject TBF items (relative to a neutral baseline) on an immediate recognition test (Experiment 3), and recalled (Experiments 1A, 1B, and 2) and recognized (Experiments 1B and 2) relatively more TBF items on delayed retention tests in which all studied items were designated as targets.In this article, we present four experiments comparing the performance of younger and older adults on directed forgetting tasks. In this type of task (e.g., see Bjork, 1989), participants are presented items to study, some of which they are told to remember and others of which they are told to forget. Because the cueing as to which items are to be remembered (TBR items) and which are to be forgotten (TBF items) occurs after the items have been presented for study, participants must pay some attention to each item as it is presented. Thus, the directed forgetting paradigm investigates the ability to forget some inputs that one has recently attended to while at the same time remembering others presented in the same context and near the same time. To the degree that one is successful at this task, as younger adults generally are, the following trends are seen: The presence of TBF items on a list does not reduce recall or recognition of TBR items; there are few intrusions of TBF items when participants are asked to report only TBR items; and performance on TBF items is relatively poor when, on a later retention test, participants are asked to report TBF as well as TBR items.