A problem-based learning (PBL) curriculum was introduced at McMaster University more than three decades ago. Not many schools have adopted the system despite its distinct advantages. The present paper examines the challenges of teaching physiology in a PBL curriculum and gleans through the literature supporting PBL. It appears that one of the reasons why PBL is not becoming readily acceptable is the lack of concrete reports evaluating the curricular outcomes. The suggestion (R. E. Thomas. Med. Educ. 31: 320-329, 1997) to standardize and internationalize all components of validated PBL curricula is quite valid. A database needs to be generated that can be easily accessed by traditional institutions to see the rationality and easy implementation of the PBL curriculum. AM. J. PHYSIOL. 277 (ADV. PHYSIOL. EDUC. 22): S140-S147, 1999.