The invention relates to a disposable absorbent incontinence diaper (2) of the open type, having a main part (4), comprising a front region (6) having front lateral longitudinal edges (42), a rear region (8) having rear lateral longitudinal edges (41) and a crotch region (10) that is located in between in the longitudinal direction (28) and comes to lie between the legs of a user, wherein the main part (4) comprises an absorbent pad (12), and having rear side portions (20) that are attached to the rear region (8) on both sides and front side portions (22) that are attached to the front region (6) on both sides, said rear and front side portions extending in the transverse direction (30) beyond the lateral front and rear longitudinal edges (42, 41) of the main part (4), and wherein the rear side portions (20) have first closure means (32) which are close to the leg opening and have closure aids and wherein the closure means (32) can be secured in a detachable manner at least on the outer side of the front side portions (22), as a result of which the front region (6) and the rear region (8) can be connected together, wherein, in order to form side-portion leg-opening regions (51, 52), the side portions (20, 22) are formed, at least on the side facing the crotch region (10), in a manner extending obliquely with respect to the longitudinal direction (28) or in a curved manner, characterized in that the length-to-width ratio R of the side-portion leg-opening region of the rear side portions (20) is 0.1-0.4, in that the tear propagation resistance Fm of the material forming the side portions is at least 4.0 N in the longitudinal direction of the diaper, and in that the spacing C of the closure means (32) close to the leg opening from the lower edge of the rear side portions is at most 5 cm.
