Contributions: This article provides valuable insights into the varying approaches of engineering students in their understanding and application of project-based learning (PBL) and its relationship with student success. The findings can be used to improve the design and implementation of effective learning environments, evaluate the effectiveness of engineering education programs, and advance the current understanding of the relationship between PBL and knowledge acquisition in engineering. Background: Previous research has demonstrated that PBL has become a significant teaching and learning method in engineering education. It has resulted in considerable progress in students’ problem-solving and critical thinking skills, teamwork, and technical concept communication. However, there is still a lack of exploration on how engineering students perceive PBL from their standpoint and how their conceptions influence student learning. This study aims to contribute to the currently limited comprehension of PBL from the students’ perspective. Research Questions: What are the qualitatively different ways engineering students conceptualize PBL, and how does PBL contribute to knowledge and skill acquisition? Methodology: A phenomenographic approach was used to gather data from engineering students who had experienced PBL in their course. Semi-structured interviews were conducted to gather rich and detailed data about the students’ conceptions of PBL. The data was then analyzed using a phenomenographic framework to identify how engineering students conceived PBL. Findings: Students’ conceptions of PBL are not uniform but vary in five different pedagogical beliefs that shape how they act in the PBL environment. The different conceptions of PBL in engineering education suggest that instructors need to communicate the learning objectives of PBL more clearly to students, and design PBL activities that cater to the diverse needs and expectations of students.