Abstract: In a hypodermic needle assembly, a needle is supported on a neoprene piston which is slidable in a tube. A syringe consisting of a barrel and a plunger is insertible into one end of the tube and connectible to, and disconnectible from, the needle by means of a Luer fitting. A projection on the plunger fits into a slot in the wall of the tube to prevent rotation of the plunger and limit its axial movement. In an alternative version, U-shaped slots in the wall of the tube provide tabs which can be manually compressed against the plunger to prevent its rotation as the syringe is connected to, and disconnected from, the needle. The assembly allows for injections from multiple syringes without removal of the needle from the patient. It also allows the needle to be withdrawn to a protected position within the tube and permits the protected needle and the syringe to be discarded separately.