A method for producing a nitrided packaging steel from a hot-rolled steel product with a carbon content of 400 to 1200 ppm, utilizing a cold-rolling of the steel product to a flat steel product, subsequent recrystallization annealing of the cold-rolled flat steel product in an annealing furnace, in particular a continuous annealing furnace. A nitrogen-containing gas is supplied into the annealing furnace and is directed at the flat steel product to introduce unbonded nitrogen into the flat steel product in an amount corresponding to a concentration of more than 100 ppm, or to increase the amount of unbonded nitrogen in the flat steel product to a concentration of more than 100 ppm, and subsequent cooling of the recrystallized annealed flat steel product at a cooling rate of at least 100 K/s directly after the recrystallization annealing. Using this method, cold-rolled flat steel products may be produced for packaging purposes with a tensile strength of more than 650 MPa and in particular between 700 and 850 MPa.