Protection motivation theory (PMT) was introduced by Rogers in 1975 and has since been widely adopted as a framework for the prediction of and intervention in health-related behavior. However. PMT remains the only major cognitive model of behavior not to have been the subject of a meta-analytic review. A quantitative review of PMT is important to assess its overall utility as a predictive model and to establish which of its variables would be most useful to address health-education interventions. The present paper provides a comprehensive introduction to PMT and its application to health-related behavior, together with a quantitative review of the applications of PMT to health-related intentions and behavior. The associations between threat- and coping-appraisal variables and intentions, and all components of the model and behavior were assessed both by meta-analysis and by vote-count procedures. Threat- and coping-appraisal components of PMT were found to be useful in the prediction of health-related intentions. The model was found to be useful in predicting concurrent behavior, but of less utility in predicting future behavior. The coping-appraisal component of the model was found to have greater predictive validity than was the threat-appraisal component. The main findings are discussed in relation to theory and research on social cognition models. The importance of the main findings to health education is also discussed, and future research directions are suggested.