We examined the developmental course of metacognition concurrently in arithmetic problem solving and in episodic memory. In Experiment 1, children aged between 8 and 13 were asked to judge the ease with which they would select the better strategy on a given item before actually selecting and executing it. In Experiments 2 and 3, children had to judge their level of confidence in a strategy once selected. Results of these experiments indicated that children are able to accurately judge whether they select the better strategy on a given item in both the arithmetic and the memory domains, and that this ability improves with age. Using a comprehensive set of metacognitive measures, our data support the hypothesis that metacognition is first domain specific and then generalizes across domains as children mature. Implications of these findings to further our understanding of age-related changes in metacognition and its involvement in strategy selection are discussed.