Experimental studies have a considerable impact on the educational policies and practices of many countries. In Turkey, policymakers are planning to initiate a STEM education reform in K-12 schools based on experimental studies. However, the methodological flaws in these studies may lead to biased outcomes and may mislead the STEM education community. Despite the importance of methodological quality, to the best of our knowledge, there are no studies that investigate the methodological quality of experimental STEM education articles published in scholarly journals. Therefore, in this study, we conducted a methodological review to examine the methodological quality of experimental STEM education articles published in refereed Turkish journals from 2014 to 2020. During the targeted period, we located 68 articles. We analyzed these articles by developing a coding framework. We found that the selected articles suffer seriously from various methodological flaws. We discuss the findings in light of the literature on methodological quality and suggest ways to improve the rigor of the experimental designs used. Ultimately, we discuss some implications for authors, journals editors, policymakers, and curriculum developers.