The aim of this study is to examine the correlation between the frequency of using metacognitive reading strategy use and non-routine problem-solving achievements in fifth grade students. The study was conducted by using the correlational survey model, one of quantitative research methods. The participants of the study consisted of 308 fifth grade students who were studying in public schools in Istanbul and Ankara in 2017-2018 school year and were selected with convenient sampling method. The data of the study were gathered using the form for the frequency of using metacognitive reading strategy by the students and the non-routine problem solving achievement Test. In the study, the form for the frequency of using metacognitive reading strategy was applied in order to determine metacognitive reading strategies of the studies and on the following day, the achievement test including non-routine problems was then applied to the students. Simple Linear Regression Analysis and Pearson Product-Moments Correlation Analysis were used in the analysis of the data obtained in the study. According to the results of the study, there was a positive correlation between the frequency of using metacognitive reading strategy and non-routine problem-solving achievements in fifth grade students and metacognitive reading strategies were a predictor of non-routine problem-solving achievement.