Abstract: An infant nursing bottle nipple is disclosed herein having an elongated feeding tip projecting from a bulbous base carried on an outwardly extending flange adapted to overlap the mouth of an infant nursing bottle. The flange includes an integrally formed reinforcement element such as a solid, rigid washer coaxially disposed with respect to the mouth of the bottle and which is of a diameter greater than the mouth so as to be placed on the bottle shoulder defining the mouth. A cap secured to the bottle bears against the reinforced flange preventing inadvertent withdrawal or displacement of the nipple during use.