A needle assembly for an injection device comprising a needle cannula which is mounted in a hub connectable to an injection device, and a biasing shield which is telescopically guided relative to the hub between a position in which the needle cannula is covered and a position in which at least the sharp end of the needle cannula is exposed, such that an injection can be performed without visual contact with the needle cannula. Further releasable locking means is provided such that the user can lock or unlock the shield to perform the telescopi-cally movement. In order to release the shield, the injection device itself can be utilized as the key for unlocking.
