Label-holder element for electrical wires (200), comprising a body (410; 510) extending in a longitudinal lengthwise direction (X-X), transverse widthwise direction (Y-Y) and vertical thickness direction (Z-Z), with a front face (10a) provided with a seat (20) for labels (30), side faces (410b) and a rear face (410c), said seat (20) having opposite top (20a) and bottom (20b) edges which extend in the transverse direction (Y-Y), are arranged opposite each other in the longitudinal direction (X-X) and are formed in the manner of engaging means (21,22) for retaining a label (30); means for coupling with an electrical wire (200) comprising at least one pair (440; 540) of teeth (441; 541) extending outwards from the rear surface (410c; 510c) in the vertical direction (Z-Z), the teeth (441; 541) of one pair having a free end (441a; 541a) directed towards the other tooth in the transverse direction (Y-Y) and being arranged staggered in the longitudinal direction (X-X) for mounting on/engagement with a wire (200).