The intricacy of real-world challenges in project-based geoscience learning is complex to assess with a STEM approach; hence, research into an effective model is necessary to address current issues in education. Understanding the role of STEM in resolving challenging real-world issues requires integrating STEM literacy that is appropriate for geoscience education. This study examines the effectiveness of the Project-Based Geoscience Learning (PJBGL) model in enhancing STEM literacy. By integrating project-based learning with geoscience, the aim is to create an interactive and immersive learning environment. The study seeks to contribute to knowledge about the effectiveness of this model compared to the conventional model. The aim was to evaluate the PJBGL model's impact on students' literacy, particularly in the geosciences. The study utilized a pretest-posttest control group design with 33 students, 19 in the experimental group and 14 in the control group, collecting STEM literacy data using a test instrument and analyzing the data with the Mann-Whitney test. Effect Size calculation using Cohen's d and increased STEM literacy was tested with the N-Gain formula. The research results show that the PJBGL model is more effective in increasing STEM literacy in geoscience learning than the conventional learning model. This finding holds implications for educators and curriculum developers seeking innovative strategies to cultivate students' STEM literacy