Abstract: The present invention relates to a protective device for use on a needle, for example hypodermic syringe. More particularly, the present invention is a capping assembly which can be used to cap or shield a needle immediately after it has been used. The capping assembly includes a generally tubular mounting member which has a tapered bore so that it can be easily slid upon, for example the barrel of a hypodermic syringe, but is difficult to remove due to the taper. Slideably mounted upon the mounting member is a sheathing member which is adapted to be slid down the mounting member to cover the needle after use. A locking member is provided between the sheathing member and the mounting member. In the preferred embodiment, the locking member included at least one protrusion extending outwardly from the mounting member and a capturing member extending inwardly from the sheathing member.