A stalk-chopper, in particular for a machine for harvesting maize, comprising a hollow casing having a central portion and two box-section arms that extend in cantilever fashion from the central portion according to a U-shaped configuration, the box-section arms being set at a distance from one another in a transverse direction and having respective distal ends set at a distance from the central portion in a longitudinal direction, two rotating output members projecting on the outside of said box-section arms at the respective distal ends of said box-section arms, the output members being carried in a rotatable way by the respective arms about respective mutually parallel axes of rotation, two rotary cutting devices connected to respective output members and having respective cutting diameters partially overlapping one another； and a transmission device housed within said hollow casing and provided for driving said output members in rotation in concordant directions.
