There is scant evidence that children younger than 7years show a memory advantage for distinct information, a memory phenomenon termed the isolation effect (Journal of Experimental Psychology: Learning, Memory, and Cognition, 2001, Vol. 27, pp. 1359–1366). We investigated whether 4-, 5-, and 6-year-olds’ developing organizational processing and executive function contributed to the isolation effect, demonstrated when recall was better for a semantically unique target (e.g., sheep, pig, watermelon, duck) rather than a semantically common target (e.g., apple, banana, watermelon, strawberry). To encourage organizational processing, children were asked to categorize each item presented. Children also completed working memory and cognitive flexibility tasks, and only children who scored high in cognitive flexibility demonstrated the isolation effect.