Writing is the basis of success at school and is one of the important means of learning and assessment in various courses. Writing is one of the most important skills that students need to acquire and improve. In recent years, it seems that in the teaching of writing, the product-based work has been replaced with the process-based one. The latter requires tracking, assessment, and correction in the process of writing; in other words, it requires running with metacognitive skills. In this study used the simultaneous mixed method. Quasi-experimental method used in the quantitative part. Qualitative research method used in order to validate and expand the quantitative data with the qualitative ones, to support the obtained data and examine them profoundly with multi perspective. The aim of this study was to discover to what extent the writing approach based on metacognitive skills would improve fourth grade students' skills in writing narrative texts, and to observe the changes occurring in their products and writing performances during the study. The study sample included 64 students in a public school in Eregli, Zonguldak (Turkey). The study used a mixed research method consisting of qualitative and quantitative methods to collect, analyze, and interpret the study data. In the implementation process, the experimental group performed their writing activities based on a process that focuses on metacognitive skills, and the control group performed their writing activities according to the Turkish curriculum. The study was conducted over eight weeks (28 hours) in the experimental group. The study analyzed students' skills in writing narrative texts and the use of metacognitive writing processes in the process of writing narrative text, and it was determined that there was a statistically significant difference between the groups to the advantage of the experimental group. It is observed that certain progress for each student in the experimental group in terms of the targeted metacognitive skills, but the control group students were not able to use such metacognitive skills adequately as tracking of the past writing, correcting when needed, or reorganizing. The results of this research are deemed to contribute to the limited literature on process-based writing skills and to help the primary school teachers enrich their teaching methods concerning the writing skill. Furthermore; the research is expected to be among the first examples in the area that emphasize the upper cognitive skills to lead further researches.