Abstract: Disposable syringe made of plastics, for medical purposes, consisting of a barrel (1), a piston (2) provided with a plunger shaft (3) guided at a distance from the barrel wall, and a closure cap (4), the piston (2) being releasably joined to the plunger shaft (3). The piston (2) is at least partially softly resilient due to the fact that on the piston periphery wall parts of greatly reduced wall thickness are present. The closure cap (4) contains a sufficiently long, stable slide bearing for the plunger shaft (3), so that deformation of the latter, arising out of off-center application of force in the retracted piston position, and out of the tendency of the relatively thin plunger shaft (3) to bow or buckle, will not be transferred to the piston (2).