Shown and described is a device for back a plumbing fixture, in particular to a wall, essentially comprising a mounting rail preferably made of metal, which contains a large number of holes, slots or the like provided for the wall mounting and to the mounting of mounting plates for a plumbing fixture, the two rail longitudinal edges being designed as attachment zones offset from the mounting level. The object of the invention is to create a new device for back mounting a plumbing fixture with which in a simple fashion a number of a plumbing fixture can be mounted to a wall with precisely the same spacing from each other and in a precise arrangement to each other. The solution of the object is the result of at least one rail longitudinal edge having a plurality of notches, slots, slits or the like, and that the mounting plates are provided with holes corresponding to the notches, slots, slits or the like, in which the screws are mounted which are fixed by anchor blocks, whereby the mounting plates are brought into a defined premounting position by the hanging of the windings of the screws in the notches of the mounting rails.