In contemporary education, critical thinking is widely recognized as one of the core competencies of the twenty-first century. This study investigates the effectiveness of Project-Based Learning (PBL) in developing students’ critical thinking skills, drawing on the experience of schools operating under the Agency for Specialized Educational Institutions (ASEI). The primary objective of the research is to determine the impact of PBL and to develop an adapted methodological model for its implementation in general secondary schools.