The authors investigated the development of metacognitive skill (MS) of 43 children from preschool to the 2nd grade (6-8 years of age) in a problem-solving situation. The children's skill to direct, guide, and monitor their performance in a play-like problem-solving context was evaluated in 3 experimental groups of preschool children with high, average, or low metacognitive knowledge (MK). The development of MS was further compared with the development of general MK of the same children. The results showed that children with initially high MK had better MS in problem-solving tasks during the 1st 2 school years, whereas the self-guided behavior of children with lower MK resembled more the type of adult-dependent behavior typical of young children as late as the 2nd grade. However, there was no clear developmental relationship between MK and MS. A number of cases from the data are described to illustrate individual differences.