Earth retaining wall (RW) structures have been used for centuries but new technologies and innovations in materials continue to emerge. While different wall types can perform the same function, a rigorous sustainability assessment protocol should be part of the selection procedure. This paper describes benchmarks for the development of sustainability assessment methods for RW structures, with criteria based on technical, environmental, economic and social factors. A wide range of materials and constructive solutions are available for RW structures. This study focuses on the most common wall types: gravity, cantilever and mechanically stabilized earth (MSE) walls (both geosynthetic and metallic reinforcement). The sustainability assessment methodology is explained and a simplified sustainability model applied to four 5 m-high RW structures falling in the three categories mentioned. The results of analyses demonstrate that MSE wall alternatives are the best solution from the sustainability point of view.