Mediterranean rural landscapes are often characterized by a complex matrix of grasslands, open wooded pastures, shrubland and broadleaf forests, and are affected by a considerable frequency of fire ignitions. Whatever the causes and the interested landscape structure, the risk of burning is related with the fuel biomass. This paper would clear the role of grazers in reducing the fire risk within 2000 ha of a typical Mediterranean Quercus spp. forest, by a modelling approach, based on FARSITE simulator, able to estimate the probability of burning, and the severity of the fires. Fuel biomass samples were collected at the start and the end of the fire season in 23 representative sites, in order to define the spatial variation of the herbaceous fuel model in grazed and non grazed conditions. Ungrazed conditions were simulated placing exclosure cages in each site. The study allowed to assess the effect of the grazing abandonment on the fire behavior. Fuel reduction strategies tested by the simulator permitted to define the role of grazers in the fire prevention plan.