Abstract: A removeable and adjustable prosthetic insert disposed between the stump of a limb and the socket of a prosthesis is comprised of a high strength, pliable polymeric material within which are formed a plurality of spaced air pockets, or voids, which are coupled together by a series of connecting channels, or passages. Using an air valve extending through the polymeric material and coupled to the closed air pocket/channel system, the air pockets may be inflated to fill the stump/socket interspace and provide a tight-fitting, air cushioned prosthetic socket attachment. The air inflatable prosthetic insert can accommodate changes in the condition of the stump and applies a uniform prosthetic attaching force thereto. Other embodiments also employ an inflatable air cushion and make use of spaced, solid spheres disposed between air passages arranged in a grid-like array; and pinched tubing with interconnecting air passages to form a series of inflatable nodules.