Health Economics published by John Wiley & Sons Ltd.In this contribution to the longstanding risk theory debate on optimal self-protection, we aim to enrich the microeconomic modeling of self-protection, in the wake of Ehrlich and Becker (1972), by exploring the representation of risk perception at the core of the Health Belief Model (HBM), a conceptual framework extremely influential in Public Health studies (Janz and Becker, 1984). In our two-period model, we highlight the crucial role of risk perception in the individual decision to adopt a preventive behavior toward a generic health risk. We discuss the optimal prevention effort engaged by an agent displaying either imperfect knowledge of the susceptibility (probability of occurrence) or the severity (magnitude of the loss) of a health hazard, or facing uncertainty on these risk components. We assess the impact of risk aversion and prudence on the optimal level of self-protection, a critical issue in the risk and insurance economic literature, yet often overlooked in HBM studies. Our results pave the way for the design of efficient information instruments to improve health prevention when risk perceptions are biased.