The aim of this paper is to discuss experimental and theoretical approaches for evaluating the geosynthetic interface behaviour under static, cyclic and dynamic loading conditions. Laboratory tests, carried out by means of pullout, direct shear, inclined plane and shaking table devices, allow obtaining the interface parameters required for the design of geotechnical and geoenvironmental structures, the choice of the more appropriate interface test depending on different limit state analysed. For each test apparatus and procedure, the factors affecting test results are highlighted. Moreover, the paper analyses the complex soil-geosynthetic interaction mechanisms that arise under different test conditions, and provides the knowledge required to properly determine the interface parameters to be used in the design of geosynthetic engineering works. Finally, the theoretical models available in literature and capable to predict the ultimate interface strength and equivalent friction are discussed in detail.