In 21st century learning, students are required to be able to face the world of work that requires the ability, one of them is critical thinking. The objective of this meta-analysis is to estimate the effectiveness of problem-based learning on critical thinking skills. This meta-analysis research method consists of some steps, they are research problem, data collection (study), data coding, data analysis, and interpretation. Based on the journal research, it is found 17 critical thinking skills journals, 17 articles that fulfill the criteria: an empirical study on problem-based learning in college and secondary education conducted in classrooms. This explanation revealed that there is a strong positive effect of Problem-based Learning on critical thinking skills. The findings of the research revealed that the results of the meta-analysis were obtained an effect size of the influence of Problem-based Learning on the dependent variable of critical thinking skills of 3,1 which is classified as high where the influence of Problem-based Learning on the dependent variable of critical thinking skills is 99.9%.