The relationship between highly desired 21st century skills, such as students' attitudes toward STEAM, critical thinking dispositions, and decision-making abilities, and the role of gender on these associations was investigated in this study. The data was collected from 4th grade students in the 2022-2023 academic year using the typical case sampling method. “STEAM Attitude Scale”, “Critical Thinking Disposition Scale” and “Decision-Making Skill Scale” were utilized. The mediation model was estimated using the whole sample, followed by multigroup analyses that employed gender as the moderation variable. The results indicated that primary school students' attitudes towards STEAM, their critical thinking dispositions, and their decision-making skills were at a high level. The mediation analysis revealed that attitudes towards STEAM had direct effect on decision-making skills, and critical thinking disposition was found to be partially mediating this association. Multigroup analyses provided evidence for the significant moderating role of gender pertaining to the specified associations in the model. The findings provide insights into the importance of developing positive attitudes towards STEAM disciplines regarding their evidential effect on critical thinking disposition and informed decision-making skills in primary schools and the necessity of attending to the role of gender in future educational interventions.