Many educational researchers have established problem-based learning (PBL) as a total approach to education--both a product and a process--from a pedagogical instructional strategy to skills development to assessment. This study provides qualitative evidences from educational practitioners in various professional disciplines, namely, Medicine, Engineering, Dentistry, and Science in Ireland and Hong Kong, on some of the identifiable issues that affect the effectiveness of the PBL process: the actual problem, the assessment, the students' pre-college learning culture and the facilitator's role. Given the increasing level of faculty interest in PBL in higher education, it is evident that training and guidelines must be provided. Moreover, clear understanding of PBL and communications between curriculum developers and PBL facilitators are vitally important for ensuring effectiveness of PBL implementation. Findings also suggest that the pre-college learning culture is least influential on PBL effectiveness, provided that students are given numerous opportunities to work collaboratively from the start of their university studies.