Modern geography education requires students to develop not only subject-specific knowledge but also the ability to independently set research problems, work with various information sources, analyze data, and formulate well-founded conclusions. The purpose of this study was to determine the impact of Project-Based Learning (PjBL) on the development of ninth-grade students' research skills in studying geography. A pedagogical experiment was conducted at Secondary School No. 43 in the Talgar district of the Almaty region. Forty-seven students from two ninth-grade classes, divided into experimental (n = 23) and control (n = 24) groups, participated in the study. A quasi-experimental pre-test/post-test control group design was used. Research skills were assessed with a nine-criterion analytic rubric including problem definition, formulation of a research question, study planning, searching for and collecting geographic data, analyzing and interpreting it, formulating conclusions, and presenting and justifying the results. The pre-test showed that the experimental and control groups were comparable. After the formative stage, students in the experimental group demonstrated a more pronounced development of research skills compared to the control group, and the post-test between-group differences were statistically significant with a large effect size (t(45) = 7.99, p < 0.001, Cohen's d = 2.33). The most significant changes were observed in the ability to define a research problem, interpret cartographic, statistical, and graphical materials, and formulate well-founded conclusions. The results indicate that the systematic use of PjBL facilitates a transition from primarily searching for and retrieving information to its independent analysis and use to solve research problems. Project-based learning can be effectively integrated into the school geography curriculum as a means of organizing consistent research activities and developing relevant skills in students.