Evidence-based medicine is spreading in popularity in many health care areas. Evidence-based medicine extends the librarians' role beyond identification of the literature to involvement in practicing and teaching quality filtering and critical appraisal of the literature. This trend requires librarians to pursue new knowledge and develop new skills. However, little discussion of the role of the librarian in evidence-based medicine appears in library and information science literature. The purpose of this paper is to investigate the evolving role of the medical librarian through the following topics: the influence of technology, quality filtering of the literature, the instruction of clinical information, and the cooperation of the librarian and the faculty.