Abstract: A safety device for agricultural machines is provided. The safety device includes a stop element, which can be associated functionally with a kinematic transmission chain interposed between a motor assembly of a working shaft and the working shaft itself to control the working shaft with the complementary stop element. The stop element is movable on command from a passive configuration to an active configuration, in which the stop element is arranged so as to interfere with the trajectory of the complementary stop element, for the forced locking of the latter and of the working shaft, and vice versa. Moreover, either or both of the stop element and the complementary stop element are associated with a unit for damping the forced locking, which can be actuated automatically upon impact of the stop element against the complementary stop element.