The invention concerns a method for placing plugs on a plug mill, the method calling for the plug, on completion of the rolling of a tube, to be removed from its position against a rod and to move downward, by virtue of its weight, out of the roller-line, to be return-cooled and then raised back into the vicinity of the roller-line. The invention calls for the plug to move along an elliptical path when being raised and to adopt, before being deposited, a holding position which is at about the same height as, and to one side of, the roller-line. The invention also concerns a device for placing the plugs, the device having a slide, a cooling device and a lifting device with two plug-change arms (1, 2) whose movement is linked by a crank gear (3). The upper arm (1) is connected to the crank gear (3) at two points while the lower arm (2) is connected to the crank gear by a push-pull rod (4) and via cranks (14, 17, 12).