Limited influence of metacognition research in mainstream classrooms may stem from a lack of comprehensive pedagogy and/or inconsistent criteria assessing metacognition instruction. For this problem, an instrument designed for metacognition instruction in reading classes was examined. After a systematic and analytic review of broad literature, scale validation procedures were followed. Items that represent observable and measurable teacher-behavior promoting students' metacognition were generated. Next, QUAID examination, expert-, cognitive-, and focus-group interviews were conducted. Data collected from reading teachers via a computer-assisted survey method were analyzed by exploratory factor analysis, Welch's, and Spearman's tests. Findings confirmed that the ITMR had a unidimensional model accounting for 60% of metacognition instruction ([alpha].97). There were no mean differences in metacognition instruction at any elementary grades. The items on the ITMR were also strongly and positively correlated. Thereby, the ITMR can be used to assist and identify classroom metacognition instruction in reading classrooms.