A chassis drive device of a garden working machine having at least one brushless motor unit 14 for driving a chassis unit 16 and having at least one gear unit 18 of single-stage form, which cooperates with the brushless motor unit 14 for driving the chassis unit 16. Preferably the gear unit comprises at least one gear element which is connected in a rotationally fixed manner to an output shaft 22 of the gear unit for driving the chassis unit. Preferably the gear unit also comprises at least one further gear element 24 which is connected in a rotationally fixed manner to a rotor element 26 of the brushless motor unit and this further gear element is formed in one piece with the rotor element. Preferably the gear unit has a gear housing 28 which is contact with the brushless motor unit.
