This paper presents the idea how to use fuzzy active rules within biometric systems. We have already shown how the concept of complex events presented in the active database theory could be used in order to build a biometric system. We especially explored the paradigm of active rules and complex events and experimental results were encouraging. Fuzzy logic is very good when dealing with imprecision and uncertainty and hence it is suitable to be used in biometric systems. We will discuss how to apply fuzzy active rules in order to deal with imprecise decision making in multimodal biometric systems.