A method for reducing nitrogen oxide emissions of a diesel vehicle. In this context, first state variables of the diesel vehicle are measured with the aid of sensors of the diesel vehicle, and using an arithmetic unit, it is ascertained, as a function of the first state variables, if the nitrogen oxide emissions are exceeding a predetermined threshold, or using the arithmetic unit, it is predicted, as a function of the first state variables, if the nitrogen oxide emissions will exceed the predetermined threshold. If exceedance of the threshold is calculated or predicted, then an intervention in the current torque demand of the diesel vehicle and/or an intervention in the current transmission ratio or setting of a transmission of the diesel vehicle is ascertained by the arithmetic unit; the intervention contributing to a reduction in the nitrogen oxide emissions to a value below the threshold.