In pressure-atomized sprays, the liquid drops and the gas in the two-phase flow field may exhibit self-similar properties, so that the spray flow as a whole may be described as self-similar [1]. This description is used to model the mass transfer from the drops to the ambient gas by evaporation of the drop liquid. The concentration of the vapour phase is described as the solution of the related, well-known transport equation in a self-similar form. The self-similar transform of the mass source of vapour representing the effect of drop evaporation is compared against profiles obtained from the Steinberger and Treybal correlation for the Sherwood number as a function of the Schmidt and Reynolds numbers. The required surface concentration is based on the wet-bulb temperature of the drops, which was determined dependent on the local vapour content at ambient air temperature. The self-similar behavior of the vapour concentration and the respective mass source remains to be validated against experiments or simulations.