A prefilled syringe includes a syringe body filled with a medical fluid, which has a nozzle at a front side, the nozzle being closed with a cap, and which is closed at a rear side with a displaceable plunger; and a plunger rod that can be inserted into the syringe body via the rear side. The plunger rod has a connecting portion at a front side, via whi9ch the plunger rod can be connected to the plunger. At least three annular elements, which extend at least in some sections about a longitudinal axis of the rod, are arranged on a rear side of the connecting portion on the plunger rod in such a manner that they are located in the syringe body when the plunger rod is fully connected to the plunger. The three annular elements support a coaxial connection of the rod to the plunger positioned in the syringe.