Abstract: An improved breathing airway comprising at least two telescopingly engaged flexible elements enabling the airway to be adjusted to the proper length to fit the mouth and pharynx of a patient. To positively secure the adjusted length of the airway, a flap with protruberances extends from the outer element and is engageable with holes in the inner element. Thus, the outer and inner engaged elements can be positively secured at the correct measured mouth to pharynx length.The untelescoped radius of curvature of each element differs from the other causing the radius of curvature of the airway to change as the elements are telescoped together. The radius of airway curvature is therefore automatically adjusted for curvature when the airway is set to desired length. Thus, one size airway of the present invention can substitute for several sizes of the prior art airways, the adjustment for the selected length automatically achieving the correct shape.