Number-plate holder for vehicles

A front and/or rear plate-holder (1) for vehicles in general is provided with at least a supporting means (6, 6', 8, 8', 8"), either integral or fastened to said plate-holder and containing at least a seat (7) for the containment and fastening of apparatuses or devices (3), positioned on the outside of vehicle. The supporting means (8") may be integral or fastened to an external frame (11) of standard size for the coupling to the plate-holder.