Mapping infiltration classes of Wallonian soils: an attempt. On the basis of the digital soil map of Wallonia (1/20,000), a decision tree is proposed for attributing infiltration class to each soil type. The proposition takes into account soil texture, drainage characteristics, substratum and, when appropriate, percentage of stoniness. The so defined infiltration classes are coherent with SCS methodology for abstraction computation (continuous or event based modelling). There are four groups named A, B, C and D from higher to lower basic infiltration rate. The map produced is a raster with a ground resolution of 10 m, covering Wallonia (16,900 km2), readily usable in hydrological distributed models. The paper deals with the classification and its inherent limitations.