Three studies are described in which age differences on a task measuring memory for delayed intentions using naturalistic stimuli were examined. A simulated street scene was constructed from a network of photographs and sounds that participants could move through using a touch screen while completing a series of event-based shopping errand instructions. The objective of the research was to identify the cognitive processes involved in the task that were vulnerable to the effects of ageing. Memory search but not cue detection was specifically affected in older persons when participants were given fewer trials to learn the instructions. There was no age specific effect on cue detection or memory search in either an unfamiliar street or one with increased levels of irrelevant visual and auditory noise. Cue detection but not memory search was disproportionately affected in older persons after filled interruptions, suggesting that the capacity for self-initiated reinstatement of working memory is reduced in old age. In general, using a computer-based simulation of a real-life task was found to be a practical means of examining the effects on behaviour and cognition of task parameters that are significant in assessing everyday memory abilities.