Reinforced shelf for metal shelving unit, particularly for the shelving units whose shelves (B1, Bn) are provided, on the side facing the public, with electronic labels and/or other peripherals, and wherein the shelf on its bottom side has plate reinforcement (T1, Tn), parallel to each other and to the front and rear side (LA, LP) of the shelf itself, characterized in that in correspondence or at the ends of the reinforcements (T1, Tn) there are provided at least a pair of apertures (1, 10) for the passage and support of wiring (D), necessary to connect means (P1) on the rear side of the shelves, to means (P2) on the front side of the shelf (B1, Bn) for supporting and displaying goods. The apertures (1, 10) are sufficiently distant from the angular bent and ribbed areas of the reinforcements (T1, Tn) so as not substantially modify the characteristics of bend strength and torsion resistance of the reinforcements. The apertures (1, 10) are preferably obtained during the manufacture of reinforcements (T1, Tn) and of relative displaying shelves (B1, Bn).