A supporting structure for an anti-noise barrier and relative assembly method are disclosed. The foundation and the structural post of the barrier are a single continuous piece in the shape of a sheet pile. The sheet pile has a first part and a second part of such a length that, in use, the second part is insertable on the ground to realize the foundation, while, contextually, the first part emerges from the ground upwards. The first part of the sheet pile, besides, is provided with connection means through which to be able to connect the sound-absorbent panels, and with a plate on which to lean the panels themselves in such a way that the arrangement on the ground of the foundation and of the structural post is results realizable in a single phase to then proceed with the second phase of application of the panels.