A needle shroud assembly for a syringe holder comprises a barrel (16), a needle shroud (24) captively telescoped relative to the forward end of the barrel (16) and retained by a top outer body (44). A locking ring (42) cooperates with the shroud, having diametrically opposed keyways which are brought into and out of axial alignment with keys (38) on the shroud (24) to free or lock the shroud from movement. The locking collar (42) is biased towards a safe position. On cocking the locking ring (42) to a live position the shroud (24) is freed for retraction movement but on return to its extended position, the locking ring is returned to its safe position.
