Meta-cognition refers to the process of active control over one’s own cognition and is essential to successful learning. It enables individuals to better manage their cognitive skills and to determine weaknesses that can be corrected by constructing new cognitive skills. Anyone who could perform a skill could think about how to perform that skill (meta-cognition). In this paper, we try to examine the relationship among meta-memory, meta-cognitive vocabulary and the role of theory of mind in Persian young children.The research sample consisted of 51 children (age range 4 to 6 years old). Children were tested at four sessions, separated by a testing interval of approximately half a year. At the first session of testing, children completed a set of theory of mind tasks. At each of the following sessions, measures of meta-cognitive vocabulary and general vocabulary as well as meta-memory were administered. Data were analyzed using ANOVA & regression analysis. Findings showed that theory of mind performance of the 4 to 6 years old children could predict meta-cognitive knowledge that was assessed about one and a half years later. Another finding was that there was reciprocal relationship between meta-cognitive vocabulary and meta-memory in that comprehension of meta-cognitive vocabulary predicted later meta-memory and, conversely, meta-memory significantly predicted later comprehension of meta-cognitive verbs. Meta-cognitive vocabulary of their own thinking processes is very important if learners are to be able to manage, organize and develop their abilities to think and learn.