A device for the wall-fixing of elongated bodies, in particular radiating coaxial cables, of the type equipped with a spacer provided with a cable clamp equipped with a lid for supporting an elongated body in a suspended position onto a wall. The spacer of the device has a structure composed of two arms, whose end facing the wall is provided with a corresponding base, whereas the opposite end of the arms carries a base for fixing to the cable clamp. With respect to the known wall-fixing devices of radiating coaxial cables, that according to the invention offers the advantage of having an improved resistance to flexural and torsional stress, also preventing interferences with the metallic part of the wall-fixing system.