The heating-ventilation and/or air-conditioning device for a motor vehicle passenger compartment comprises modules grouped substantially at the same horizontal level, namely at least one ventilation module (14) arranged to produce a pulsed air flow, a heating module (12) to be located in a central region of the passenger compartment and having heat exchangers (32, 34, 36) through which the air flow from the ventilation module can pass, and at least one distribution module (16) having an air inlet connected to a side air outlet (46d, 46g) of the heating module. The device of this invention may be installed in a vehicle passenger compartment having no central console.