Abstract: The present invention relates to a self-sealing flexible plastic valve for a non-latex balloon, to a balloon incorporating such a valve, to a method of manufacturing such a valve, and to a method of manufacturing a balloon incorporating such a valve. The valve is made from two flexible plastic strips, bonded together along the side edges to define a valve passageway or tube, and having an open inlet end and an open outlet end. The inlet end of one or both valve strips flares or otherwise curls outwardly to facilitate opening of the valve to insert a gas supply mechanism to inflate the balloon.