In this paper we propose a method to produce maps of fie danger index (FDI). The index includes in the formula a vegetation pyrogenic potential index (VPPI) based on flristic phytosociological data. The map of FDI is produced by integrating available phytosociological maps of vegetation, geomorphology and climate, using the Geographic Information System technology. The method is applied to an area of the coastal Classical Karst (NE-Italy). While fie risk maps based on the incidence of previous fies are useful for facilitating emergency operations, e.g. the allocation of fie fihting resources, we conclude that the proposed index offrs an effctive tool to plan actions for fie prevention.