The invention relates to a device for delivering ventilation air to the front of the cabin (6) of a motor vehicle, this ventilation air being delivered by a delivery box (11) of a heating, ventilation and/or air-conditioning unit, said device comprising at least one ventilation pipe (9) supplying at least one air vent (16a, 16b, 17a, 17b) provided in the dashboard (1), said ventilation pipe (9) being formed in a delivery module (8) which runs transversely under the upper face (2) of the dashboard (1), and splitting downstream in the direction of flow of the ventilation air into at least one nullgentlenull ventilation pipe (13) which opens onto the, upper face (2) of the dashboard (1) via ventilation orifices (14) of large cross section and into at least one nullforcednull ventilation pipe (15) which supplies at least one air vent (16a, 16b, 17a, 17b) of small cross section arranged on the dashboard (1) facing the cabin (6). At least one air distribution shutter (21) is provided at the junction between the three pipes (9, 13, 15.