Abstract: An inflatable closing plug for pipes and a method of manufacturing same. The plug includes a unitary balloon-like element of elastic material, and a wire located on and adhered to the outer surface of the balloon-like element. The wire extends from the first end of the balloon-like element to the second end of the balloon-like element, and has a coefficient of elasticity which is less than the coefficient of elasticity of the elastic material of the balloon-like element. The plug can expand freely in the radial direction and is bounded in axial sense by the longitudinal wire or wires, in order to permit a sufficient closing pressure to be achieved. To manufacture the plug the balloon-like element is inflated to a predetermined pressure. At least one wire is placed on the outer surface of the inflated balloon-like element between its two ends, and adhered thereto.