Problem-based learning (PBL) has been implemented with different levels of success in first-year engineering education in response to the rapidly growing requirements for a higher degree of learner agency in graduates. This study is contextualised in a systemic problem-based learning environment and explores the sources of first-year engineering students' learner agency development in relation to the main features and skillsets of PBL, such as teamwork, student-centredness, problem orientation and project organisation. Q methodology was employed, including both qualitative and quantitative data collection and analysis based on a 39-statement Q sample and 102 valid Q sorts. The Q analysis identified four statistically distinct viewpoints on the key sources of learner agency for students: (1) Team dynamism and self-directed learning within the project team, (2) Trust and peer support within the project team, (3) Individual efforts at career readiness and (4) Team efforts at project management. The findings highlight the potential of PBL for offering more and better pedagogical support for first-year engineering students in developing learner agency.