This study aims to determine the effect of learning activities conducted in accordance with the phenomenon-based learning approach on the metacognitive awareness level of students. Pre-test and post-test control group design of the experimental method was used. The application of the study was carried out in a sample of 60 students studying in the 7th grade of middle school in the 2019-2020 academic year. While "phenomenon-based learning approach" was implemented in the experimental group, traditional teaching was used in the control group. In this research, as data collection tool "metacognitive awareness" scale was used. The scores of the experimental and control groups obtained from the scale were compared to the dependent groups with the t-test, and when there was a significant difference between the students' pre-test scores and post-test scores, the effect size of the difference was found by looking at the Cohen's "d" value. In addition, when the pre-test scores of the students in the experimental group and the control group were taken under control, covariance analysis was conducted to determine whether there was a significant difference according to the post-test scores. According to the indications obtained at the end of the research teaching activities conducted in accordance with the phenomenon-based learning approach provided significant differences in the metacognitive awareness levels of the students in favor of the experimental group.