Risk is defined, for management purposes, as the potential economic, social and environmental consequences of hazardous events that may occur in a specified period of time. The risk requires a multidisciplinary evaluation that takes into account not only the expected physical damage but also the conditions related to social fragility and lack of resilience conditions, which favour the second order effects when a hazard event strikes an urban centre. The proposed method of urban risk evaluation uses the fuzzy sets theory in order to manage qualitative concepts and variables involved in the evaluation.