Objective: This paper aims to discuss the classical measures of risk assessment and proposals by means of the fuzzy sets theory. The vagueness, uncertainty and vague terms are recurring in the definitions and treatment of events in healthcare and are typical characteristics of the phenomena in such an area. Epidemiological studies have not often weighted these uncertainties tough, and risk measures classically proposed dichotomize the subjects and phenomena, when in practice the boundaries between these divisions are not as much accurate as they are treated. Method: The fuzzy sets theory can be useful in the treatment of uncertainties in human events and shows up as a theory of promising application in epidemiologic research. The fuzzy risk measures have been formalized, requiring their use in real cases. Conclusion: The fuzzy sets theory may contribute to the treatment of uncertainty and subjectivity inherent to epidemiological phenomena. This article aims to contribute to the discussion of fuzzy risk measures. Their use will allow the classification of subjects and events in sets of more flexible limits, contributing to the dissemination of promising partnership that may arise between the fuzzy theory and epidemiology. DESCRIPTORS: Epidemiology. Measures of Disease Occurrence. Public Health. Odds Ratio.