There is described a weather stripping comprising an anchor portion (2) that can be fastened along a perimetric edge (3a) of an aperture (3) that can be closed by a door (4), and a tubular sealing portion (9) fastened along the anchor portion (2). The sealing portion (9) is elastically deformable, following the closing of the door (4), from an at rest state wherein it has a substantially curved transversal crosssectional contour, to an operating state wherein said transversal cross-sectional contour is elastically deformed by compression. The internal perimetric edge of the transversal cross-sectional contour has three recesses (11, 12, 13) which, together with the connecting area (9a) of the sealing portion (9) on the anchor portion (2), define four hinges, due to the effect of which the sealing portion (9), in passing from the free state to the operating state, behaves like a deformable parallelogram.