Even if we have acquired a good knowledge of wetlands’ ecology and classification, quantification of the abundance of wetland types and delineation of homogeneous regions in terms of wetland habitats are still lacking in forest dominated landscapes. The most limiting factor for coarse-scale studies of wetlands is clearly the absence of a precise and reliable wetland spatial database available at low costs. Our objective is thus to develop such a tool based on forest inventory maps. A distribution study of wetlands was conducted on a 540,000 km2 area located in boreal Quebec. A total of 448 numerical forest inventory map leaflets systematically distributed were chosen, covering 20% of the study area. Using GIS rules and queries, it was possible to discriminate several types of deepwater and wetland habitats of faunal interest according to a classification system inspired from Rempel’s (1997) wetland habitat classification for boreal forest waterfowl and adapted by Breton (2005) (Ménard et al. 2006). Results evidenced the spatial heterogeneity, richness and complexity of the wetlands found in our study area. On average, wetlands and deepwater occupy respectively 11.7 % and 10.3 % of the study area but these proportions showed considerable spatial variation. We conclude that forest inventory maps can be used to quantify the area of wetland habitats and to define homogeneous regions in this regard, and therefore provide a functional tool for coarse-scale wetland management and protection.