A vehicle air-conditioning system (1) includes an HVAC unit (2) in which a first refrigerant evaporator (6) and a second refrigerant condenser (7) are disposed in an air channel (5) communicating with a vehicle interior space; and a heat pump cycle (3) in which a refrigerant compressor (8), a refrigerant switching device (9), a first refrigerant condenser (10) that exchanges heat with the outside air, a first expansion valve (13), and a first refrigerant evaporator (6) are connected in sequence and in which the second refrigerant condenser (7) is connected in parallel with the first refrigerant condenser (10) via the refrigerant switching device (9). An exhaust-heat recovery circuit (21) equipped with a second refrigerant evaporator (16) disposed in a ventilation channel (17) from the vehicle interior and a second expansion valve (15) is connected in parallel with the first expansion valve (13) and the first refrigerant evaporator (6) of the heat pump cycle (3).