The term ‘tacit’ is used to describe knowledge that is not necessarily understood in words. We frequently make use of such knowledge without conscious awareness that we are doing so. This article explores two different conceptions of tacit knowledge and considers their implications for the clinical teaching of dentistry. It recognises the communication barrier that clinical dependence on tacit knowledge creates between teacher and student. It identifies the ability to surface tacit clinical knowledge for the student as one of the most significant skills of the clinical teacher. Finally, the article examines the potential for conflict between the evidence-based practice paradigm, with its dependence on codified, explicit knowledge and the notion of clinical practice, which is at least partly experiential and tacit.