Abstract: A protective assembly for use with needle-bearing injector devices includes a pair of cylindrical sleeve members, initially concentrically disposed relative one another and adapted to be fitted about a conventional hypodermic syringe assembly. Prior to use of the injector device, the protective assembly is slipped over the needle, which is preferably covered by a sheath, until a latch mechanism on an inner one of the sleeves becomes locked between the hub of the needle and the forward portion of the syringe barrel. Following use of the injector device, an outer one of the sleeves is displaced forwardly until a latch mechanism adjacent its rear portion snap-fits within a catch provision on the forward portion of the inner sleeve, thus providing a post-use position wherein the syringe needle is fully peripherally surrounded by the extension of the outer sleeve.