Robert Maillart’s contribution to the community of civil engineers and, most of all, his crucial role in the evolution of the structural art are undeniable. He was able to merge not only mechanical efficiency with innovative solutions but also aesthetic expression as a real artist, always balancing his choices with limited resources both in terms of construction materials and costs. Following these three key parameters he succeeded in producing structures which can be considered a very good combination of structural performance and sustainability. The actual goal is to understand to what extent Maillart’s bridges are indeed sustainable in addition to be efficient and elegant.