Background: This article describes the application of problem-based learning (PBL) to a single discipline in a traditional medical curriculum. It covers the preparatory stages and the initial 3 years. Description: Preparatory workshops took place with emphasis on tutor training and the use of appropriate learning materials. The PBL format applied was the tutorial process supported by PBL modules (paper simulations based on complete clinical cases). Evaluation: Students' PBL skills were assessed during the sessions, and the final examination consisted of a multiple-choice test (MCT). Students with higher PBL marks also scored significantly higher in the final MCT. Both students and teachers found the method motivating and useful in the learning of pathophysiology. Conclusions: A detailed PBL format was applied to a single discipline without major curricular changes. Although the effects on other disciplines are still minor, the project allowed for the development of educational activities at the institutional level, including the establishment of a Department of Medical Education.