 This meta-analysis study found that the problem-based learning, PBL, approach has a higher effect size than the traditional instructional approach when it comes to improving student academic achievement in science classes. The study also revealed that the effect size varied depending on the type of publication, conference paper, article, master's thesis, or doctoral thesis, country of origin, educational level, and subject area. Additionally, the study found no significant difference in the effect size between different variations of PBL instruction and different science topics. Based on these findings, this study suggests that incorporating innovative teaching methods into PBL may be beneficial for researchers looking to investigate how such methods can improve student academic achievement in science courses. This article was authored by Eufuck Ulusna.