To examine how children's fantasy beliefs can affect memory for their experiences, 5- and 6-year-olds with differing levels of belief in the reality of the Tooth Fairy were prompted to recall their most recent primary tooth loss in either a truthful or fun manner. Many of the children who fully believed in the existence of the Tooth Fairy reported supernatural experiences consistent with the myth under both sets of recall instructions, whereas those who realized the fictionality of the myth recalled mainly realistic experiences. However, those children with equivocal beliefs evidenced a different pattern under each set of instructions, recalling mainly realistic experiences when asked to be truthful and reporting many fantastical experiences when prompted to relate the tooth loss in a fun manner. These findings suggest that children's beliefs in the reality of fantastic phenomena can give rise to genuine constructive memory errors in line with their fantasies. Copyright © 2007 John Wiley & Sons, Ltd.