This study explored the implementation of a project curriculum in an elementary school and analyzed the effect of the curriculum on learning effectiveness. A case study approach was employed, and third-grade teachers and students from an experimental school were recruited. Data were collected using interviews, classroom observations, document reviews, and questionnaires. The findings revealed a curriculum cycle comprising four phases: project introduction, thinking and exploration, presentation, and reflection. This process fostered competency development, enhanced problem-solving skills, supported the development of multiple intelligences, and improved thinking and communication. Teachers effectively used resources to overcome challenges and promote learning effectiveness.