The aim of this study is to develop a model for the evaluation of the vulnerability of infrastructures to forest fires in Wildland-Urban Interfaces (WUI). The model, developed using GIS, permits the exposition of the different grades of infrastructure vulnerability through the use of dedicated maps, and the analysis of factors which are most significant in determining a specific level of vulnerability. The factors introduced in the model are: types of vegetation, historical number of fire incidents, slope, and operational difficulties relative to fire suppression. A Multi-Criteria Analysis technique (Analytic Hierarchy Process - AHP) was used to compare the data, and fuzzy logic functions were adopted in an attempt to reduce errors. The AHP was based on interviews with experts (operative room managers, firebosses, researchers). The final product was a pixel map classifying five levels of risk which may prove useful to decision makers in planning prevention action and in establishing priorities.