The Deese-Roediger-McDermott (DRM) paradigm was manipulated in order to look at the development of semantic false memories. Short and long DRM lists were presented to children aged 5, 7 and 10 years either in list form or embedded within a story that was consistent with the theme. At test critical lures, targets and unrelated lures were presented for recognition. Opposite developmental trends were observed for lists and stories. Longer lists produced more false alarms to critical lures for 7 and 10 year olds only and longer stories produced more false alarms to critical lures for 5 year olds only. When overall presentation time of materials was controlled, these Age x Length interactions were absent. These results demonstrate that increasing the number of presented items only increases false memory when the theme of the items is made salient and also that presentation duration is a crucial factor at all ages.