An air supply system for a pneumatic loom contains a primary or main nozzle and a number of auxiliary nozzles. A pressurized or compressed air container or reservoir is connected by means of a primary or main control valve with a pressure line or conduit. The auxiliary nozzles are connected with the compressed air container. The primary nozzle is connected by a line with the primary control valve. This line extends, in the direction of the primary nozzle, through a pressure regulation valve and a control valve. Directly forwardly of the control valve there is arranged a compressed air storage. Consequently, there is obtained the beneficial result that the pressure in the primary nozzle, each time that the loom is placed into operation, always reaches its operating value as rapidly as possible. Thus, it is possible to dispense with the need to increase such pressure and the weft thread or filling is therefore less markedly loaded.