The present study investigated the development of the memorability-based strategy, a metacognitive process through which individuals reject the occurrence of false events if they do not remember the events and they expect them to be highly memorable. Previous research found that only older children spontaneously use this strategy. In the present study, we examined whether providing children with relevant information about expected event-memorability and inferences derived from it induced strategy use. Children aged 5, 7, and 9 (n = 144) were asked about true and false (high- and low-memorability) autobiographical events. Participants were either interviewed according to the standard "lost-in-the-mall" procedure, or were additionally provided with warnings. Warnings were either congruent or incongruent with assessments and decision processes involved in the strategy use. Results showed that receiving memorability-congruent warnings increased false-event rejection rates in 7- and 9-year-olds, but not in 5-year-olds. However, only older children were more likely to reject high-memorability compared with low-memorability false events. Developmental trajectories and factors affecting reliance on the memorability-based strategy are discussed.