The present study aimed to review master’s and doctoral theses, articles and proceedings on the impact of concept maps on academic achievement and published between 2005 and 2017, and to analyze the common effect size with the meta-analysis method. In the study, the effect sizes reported in 78 studies on the effect of concept maps on academic achievement and the overall effect size reported in these studies were analyzed. The Comprehensive Meta-Analysis software was employed in data analysis. In the study, interpretations were conducted based on the effect size index published by Cohen (1988) . The studies included in the meta-analysis were combined and it was determined that the structure was heterogeneous. Thus, the calculations were conducted with the random effects model in the study. The analysis findings demonstrated that the impact of the concept maps was 1.08 on academic achievement; thus, the effect was categorized as strong and positive based on Cohen’s (Cohen, 1988)  classification. It was concluded that
the concept maps were quite effective in the improvement of the academic achievements of the students and could be employed in education.