This study aims to analyze the effectiveness of the implementation of the Problem-Based Learning (PBL) learning model in improving student learning outcomes in the material Welcoming the Age of Puberty in grade IV of SDN 106210 Rambung Besar. This study uses the Classroom Action Research (CAR) method which is carried out in two cycles, with stages of planning, implementation, observation, and reflection. The subjects of the study were grade IV students of SDN 106210 Rambung Besar. Data were collected through learning outcome tests, observations of student and teacher activities, and interviews. The results of the study showed that the implementation of the PBL model can significantly improve student learning outcomes. In the first cycle, the average student score increased compared to the conditions before the action. The second cycle showed further improvements in conceptual understanding, critical thinking skills, and student activity. The PBL model also encourages students to be more active in discussing, working together, and solving problems related to the material being studied. The conclusion of this study is that the PBL learning model is effective in improving student learning outcomes in the material Welcoming the Age of Puberty. Therefore, it is recommended for teachers to adopt this model as an innovative learning strategy to improve the quality of learning in elementary schools