A drive device (1) for an electric bicycle, in particular for a Pedelec which is operated in a hybrid fashion by electric motor and with muscle force, contains a drive housing (7) in which a hollow shaft (3) is mounted, which is connected to a sprocket wheel (11) of a chain transmission of the electric bicycle, a pedal crankshaft (2) which is arranged coaxially with respect to the hollow shaft (3) and is connected at both ends to pedal cranks, a first clutch which is shifted as a function of the direction of rotation and which is arranged between the hollow shaft (3) and the pedal crankshaft (2), and an electric motor (4) whose output is connected to the hollow shaft via a second clutch which is shifted as a function of the direction of rotation. A device for actuating a back-pedalling brake is arranged between the pedal crankshaft (2) and the hollow shaft (3), which device runs freely in the event of coupling of the pedal crankshaft (2) to the hollow shaft (3) by the first clutch which is shifted as a function of the direction of rotation, and couples the pedal crankshaft (2) to the hollow shaft (3) in the opposite direction of rotation.