This paper presents a method of calculating the physical absorption of low concentrated gaseous nitrogen oxides in liquid nitric acid solutions. This absorption is used in the absorptive-regenerative process (AR process) to reduce the nitrogen oxide content in the exhaust gas from nitric acid plants. This method consists of the calculation of the effectiveness of the absorption in dependence on the liquid/gas ratio, the number of theoretical shelves adequate to the absorption system and other parameters of the process. The paper presents some results of calculations based on, for example, the accepted values of the initial parameters of the process. Conclusions formulated in this paper result from the calculations and concern the rational formation of the AR process as a whole and especially, the stage of regeneration.