The invention relates to a multi-zone air conditioning system for vehicles (1) with several air conditioning zones (2), in particular for buses, characterized thereby that an air temperature control unit (3) is implemented to generate simultaneously warm air and cold air, wherein the cold air across a cold air duct (5) and the warm air across a warm air duct (6) extend separated from one another as a double conduit over the length of the vehicle (1) and that decentralized air mixing units (4) with at least one air outlet (20) are disposed along the double conduit and that the air outlets (20) are assigned to the air conditioning zones (2) of the vehicle (1).