Abstract: An erection aid comprises an annnular elastic tube which is inflatable to apply pressure to the base of the penis, reducing venous flow of blood while permitting arterial flow. A valve is provided for inflation. The annular tube is made with non-uniform wall thickness so that the inwardly facing portions of the wall are thinner and more easily deformable, permitting the desired pressure to be applied while minimizing axial deformation and thereby minimizing interference with normal functions. The thicker portions of the tube are sufficiently elastic to allow diametral increases as the penis becomes erect.