After having delineated the concept of risk and having described the type of risks that are relevant to dental practice, an overview of empirical and theoretical work on risk perception is given. The perception of risks is determined both by the actual magnitude and by perceptual bias, originating from either general perceptual phenomena such as (cognitive) availability or the ego-relevance of risks: persons in general underestimate risks for themselves as compared to the risks for others (unrealistic optimism).