Abstract: A non-reusable hypodermic syringe is provided which comprises an elongated cylinder open at one end and substantially closed at the opposite other end. A hollow member is formed on the other end, which hollow end defines an internal duct communicating with the interior of the cylinder. The hollow member is configured and dimensioned to have a hypodermic needle affixed to it. The syringe plunger is comprised of a substantially rigid shaft and a resilient piston releasably attached to a first end of the shaft member. The piston fits into the interior of the cylinder in longitudinally sliding, frictional sealing engagement therewith. An engagement member is positioned on the piston member, and a retention member is positioned on the interior wall of the cylinder adjacent to, but spaced from the other end of the cylinder.