An automated methodology for the inventory of wetlands in Uruguay was designed, defining a specific technical criteria for their determination. It was necessary to use a combination of procedures and technological tools (Remote Sensing, Digital Photogrammetry, GIS) to process the available information. The following data has been considered: very low sloped terrains (out of a digital terrain model), soils with characteristical moisture behavior, basins and areas with hydrophile vegetation (using satellite images classification). All these variables have been combined in a categorization algorithm to produce specific thematic cartography.