As a consequence of the polarisation of dental caries, which occurred over the last 3 decades in industrialised countries, the usefulness of risk assessment, both for individuals and for groups of subjects, became evident. At individual level, the early identification of high and medium caries-risk subjects allows to plan specific preventive measures for each subject's needs, based on the risk grade and the causally-directed diagnosis. At population level, risk assessment helps to increase the efficiency and to reduce the costs of caries preventive programmes. In this study, a review of caries-risk indicators is proposed: these indicators, collected through the analysis of relevant background data, clinical examination and salivary tests are indispensable to achieve a correct caries-risk assessment. A review of the studies on the attempts to produce prediction models for caries-risk assessment is presented: in view of the multifactorial nature of caries etiology and the complexity of the prediction of individual caries-risk, a multivariate approach is necessary. Finally, some suggestions on the clinical usefulness and on indications of caries-risk determination are given.