BACKGROUND: Evidence-based medicine recognizes that clinical expertise gained through experience is essential to good medical practice. However, it is not known what beliefs clinicians hold about how personal clinical experience and scientific knowledge contribute to their clinical decision making and how those beliefs vary between professions, which themselves vary along relevant characteristics, such as their evidence base. DESIGN: We investigate how years in the profession influence health care professionals' beliefs about science and their clinical experience through surveys administered to random samples of Swedish physicians, nurses, occupational therapists, dentists, and dental hygienists. The sampling frame was each profession's most recent occupational registry. RESULTS: Participants ( = 1,627, 46% response rate) viewed science as more important for decision making, more certain, and more systematic than experience. Differences among the professions were greatest for systematicity, where physicians saw the largest gap between the 2 types of knowledge across all levels of professional experience. The effect of years in the profession varied; it had little effect on assessments of importance across all professions but otherwise tended to decrease the difference between assessments of science and experience. Physicians placed the greatest emphasis on science over clinical experience among the 5 professions surveyed. CONCLUSIONS: Health care professions appear to share some attitudes toward professional knowledge, despite the variation in the age of the professions and the scientific knowledge base available to practitioners. Training and policy making about clinical decision making might improve by accounting for the ways in which knowledge is understood across the professions. HIGHLIGHTS: Study participants, representing 5 health care professions-medicine, nursing, occupational therapy, dentistry, and dental hygiene-viewed science as more important for decision making, more certain, and more systematic than their personal clinical experience.Of all the professions represented in the study, physicians saw the greatest differences between the 2 types of knowledge.The effect of years of professional experience varied but tended to be small, attenuating the differences seen between science and clinical experience.