<![CDATA[Sustainable development has become one of the pressing global challenges that must be instilled from an early age so that the younger generation develops awareness of and responsibility toward the future of the environment, society, and economy. Elementary school is a strategic stage for cultivating such understanding, yet textual and less contextual instruction often fails to build meaningful sustainability awareness among students. Project Based Learning (PjBL) is believed to be an approach capable of providing authentic learning experiences, enabling students not only to cognitively understand the concept of sustainable development but also to internalize its values through real action. This study aims to describe the implementation of project-based learning in fostering understanding of sustainable development among fifth-grade students at SDN 157/III Pendung Mudik. The study employed a qualitative descriptive approach involving 13 fifth-grade students as research subjects. Data were collected through participatory observation, semi-structured interviews, and documentation during the implementation of an environment- and sustainability-themed project, then analyzed using data reduction, data display, and conclusion-drawing techniques. The results show that project-based learning was able to enhance students' understanding of sustainable development concepts, marked by increased active participation, critical thinking ability, collaboration, and concern for environmental and social issues around them. Nevertheless, several obstacles were found, including limited time allocation, limited project-supporting facilities, and variation in students' ability to work in groups. This study recommends strengthening teacher facilitation and providing contextual learning resources to optimize the implementation of sustainability-themed project-based learning in elementary schools.]]>
