A power take-off device for an agricultural vehicle, in particular a tractor, wherein an input shaft is connected to a first and, selectively, a second output shaft by moving a sleeve-type selector between three selection positions, in the first of which, the input shaft is connected angularly to the first output shaft to rotate the first output shaft at a first speed, and in the second and third of which, the input shaft is connected angularly to the second output shaft to rotate the second output shaft at a second speed and a third speed, different from the second speed.