A protection motivation theory is proposed that postulates the three crucial components of a fear appeal to be (a) the magnitude of noxiousness of a depicted event; (b) the probability of that event's occurrence; and (c) the efficacy of a protective response. Each of these communication variables initiates corresponding cognitive appraisal processes that mediate attitude change. The proposed conceptualization is a special case of a more comprehensive theoretical schema: expectancy-value theories. Several suggestions are offered for reinterpreting existing data, designing new types of empirical research, and making future studies more comparable. Finally, the principal advantages of protection motivation theory over the rival formulations of Janis and Leventhal are discussed.