A shift device for a power take-off transmission. An input shaft is connectable to an output shaft with three gear pairs. The output shaft has a recess, in which a PTO stub shaft can be reversibly introduced. A mechanism, actuated by a PTO stub shaft actuates a gearshift sleeve, provided on the output shaft and rotationally fixed to the output shaft, is provided on the output shaft. In one shift position of the gearshift sleeve is rotationally fixed to a gear wheel of a first gear pair. In another shift position of the gearshift sleeve no fixed connection exists between the gearshift sleeve and gear wheel of the first gear pair. By means of a further gearshift sleeve a rotationally fixed connection can be established with a gear wheel of the second or the third gear pair.