A drive device (1) for an adjustment device for adjusting a vehicle part, in particular a window opener, comprises a carrier element (4), a cable drum (3) and a cable output housing (2) which can be arranged on the carrier element (4), mounts the cable drum (3) rotatably about an axis of rotation (D) and can be fitted with at least one housing portion (21) onto the carrier element (4). A motor unit (8) serves for driving the cable drum (3) by electric motor. In addition, it is provided that the carrier element (4) has a bearing structure (450) with a plurality of elevations (451) and depressions (452) lined up next to one another and arranged in an alternating manner with respect to one another, and the at least one housing portion (21) of the cable output housing (2) can be fitted with abase portion (210) onto the bearing structure (450). A drive device which is in particular straightforward to fit and can have a favourable operating behavior during operation is thereby provided.