The aim of this paper is to provide the criteria for the selection of the suitable of geocells for a given slope. The suggested design procedure allows to take into account the application of the geocells both on a soil slope and on a slope waterproofed with a smooth geomembrane. This latter case covers the use of geocells for capping of landfills and for other common applications. The design method considers the resistance of the junctions of the geocells and allows to detennine the n1J111ber of gs or staples required to anchor the geocells to the ground without junctions fail1Jre. In case of use of the geocells on a, smooth geomembrane, a geogrid is placed between geocells and geomembrane: the design method allows to determine the strength req1Ji1ed for the geogtid. The design nwthod presented in the paper is based on theoretical considerations, laboratory tests and field experience of the modes of fail1J:re.