A syringe for a high-pressure injector, having a syringe cylinder with a tube connection for a tube line located at an end closer to the patient and having a plunger that is guided inside the syringe cylinder in an advancing direction and that has sealing surfaces for resting in a sealed fashion against an inner wall of the syringe cylinder. The plunger is embodied as a two-component injection-molded part based on thermoplastic plastic with a core piece composed of a harder plastic and a covering layer that is mounted on the core piece and is composed of a comparatively softer material. The covering layer constitutes or forms at least the sealing surfaces and the plunger surface of the plunger oriented toward the end of the syringe cylinder closer to the patient. The plunger is embodied with or has openings in the region of its plunger surface.