Abstract: The invention relates to a fuel injection nozzle for an internal combustion engine, especially of a common-rail injection system. The injection nozzle contains a nozzle needle which is coupled to an actuating element that serves to control a nozzle opening process. The nozzle needle comprises a needle point and a valve seat which interacts with the same. The valve seat has a conical sealing surface with an opening angle &agr;1, and the needle point has a conical sealing surface with an opening angle &agr;2. The opening angle &agr;2 of the sealing surface of the needle point is smaller than the opening angle &agr;1 sealing surface of valve seat. An expansion, said expansion serving as a cavitation chamber, of a ring-shaped flow channel, is configured between the needle point and the needle housing in the direction of flow of the fuel following the sealing surfaces of the needle point and valve seat. The cavitation chamber is configured and dimensioned to achieve a targeted cavitation results.