Drive of a seat adjusting device, especially for motor vehicles, with a spindle that is fastened on a first of two rails, which are adjustable with respect to each other, by means of at least one mounting located at the end of the spindle and with a transmission driven by a motor that is mounted on the second rail, whereby the mounting has one part as a base plate, from which two walls at a distance from each other extend upward and that at least one end of the spindle is fastened between these two walls.