This communication represents the 3rd of a series of publications about some McMaster students' perspectives on learning in a genuine PBL environment. Emphasis in this communication is placed on early clinical exposure as an essential element in a PBL medical curriculum. A decade ago, a survey of 60 medical schools in the U.S. indicated only 4 schools offered 40-50 hours courses of clinical skills to medical students and these clinical electives were offered mainly as lectures and demonstrations, primarily delivered by faculty. Despite the advancement in information technology and educational conceptualization, which revolutionize the clinical training in medical education, there are still skeptics about student-centered clinical training and advocates for faculty-centered bed-side teaching. Here, based on the personal experience of a group of the first year medical students during their first 12 weeks at McMaster University, we describe how early clinical exposure can be integrated with basic science learning in a student-centered, self-directed manner across the entire PBL curriculum. It is emphasized that early clinical exposure, especially in the first year, is meant to offer the students the basics of professional skills including communication as well as basic physical examinations, and to foster students; skills in clinical reasoning via understanding of the clinical relevance of the basic knowledge, which they are to search and learn in a self-directed manner. Although proper early clinical exposure is not aimed to train the students to be professionally competent in clinical problem-solving at this stage, but it will almost inevitably have a spin-off benefit for their clinical endeavor in future senior years of medical education. On the whole, medical students newly embarking on their McMaster medical training often describe early clinical exposure as an unforgettable catalyst to their first twelve weeks of learning.