Abstract: A disposable auto-destruct syringe is disclosed which includes a syringe barrel for holding an injectable fluid, a piston reciprocatable in the barrel and sealingly engaging the barrel wall, a plunger having a forward portion normally positioned in the barrel and a rearward portion to be manipulated by a user of the syringe, a coupling mechanism for connecting the piston with the plunger to permit axial movement of the piston in the barrel by operation of the plunger, and a deforming structure for permanently deforming the barrel wall to break the seal between the piston and the barrel wall. The deforming structure is in the form of cutters or burrowing elements mounted by-way of elastic arms to one of the piston and the plunger. The deforming structure is movable from an at rest position wherein the barrel wall is not deformed, to a barrel wall engaging position wherein the barrel wall is permanently deformed by the deforming structure.