There has been a growing adoption of problem-based learning (PBL) strategies internationally -- in health science and non-health departments in tertiary institutions and colleges. Many studies extol the effectiveness of PBL by its credibility in student learning. Few or no studies ever attempt to relate the quality-assurance system and tutors' belief in PBL courses. The aim of this study was to obtain insight into the effect of the quality- assurance system on tutors' espoused belief and belief-in-practice in PBL-based courses in three universities of Hong Kong. A total of nine research teams (each consisting of a few PBL tutors) were involved. Before the implementation of PBL, the tutors attended specific orientation and training sessions on PBL. Twelve tutors were randomly selected for interview after the implementation. The findings from this study indicated that the majority of tutors who joined this research team had a student-centred teaching belief, which was in no way related to the training sessions provided by this project. Most of them found PBL encouraging in promoting students' critical thinking skills and classroom atmosphere. However, all of them indicated that the preparatory time and resource requirement of a PBL-course were more than a conventional course. In addition, tutors found it hard to buy out more time for PBL teaching because of the requirement of research output (i.e. the quality assurance index for individual faculty member). These constraints dictated by the resources and quality assurance index of the departments will increase the gap between the espoused theory of teaching and belief-in-practice.