The RUSLE (Revised Universal Soil Loss Equation) (Renard, Foster, Weesies, & Porter, 1991) is an empirical model estimating the annual loss of soil due to surface erosion processes (sheet, interril and rill). This work calculates the annual amount of erosion in the little hilly catchment of Rio Centonara, in Bologna Province, Italy, based on catchment properties and measured precipitation rates, and compares resulting estimates with long-term field measurements. Both field measurements and GIS-based routine for the period 2006-2009 give a mean soil erosion rate of 35 t ha-1 y-1. Although the study has been originally developed as a practical exercise for teaching purposes, considering the good estimate of the erosion rate given by GRASS GIS 7.0, it could be considered as a good example of a GRASS GIS routine applied in environmental and hydrological studies.