The maximum entropy principle (MEP), which has been popular in the modeling of droplet size and velocity distribution in sprays, is, strictly speaking, only applicable for isolated systems in thermodynamic equilibrium; whereas the spray formation processes are irreversible and nonisolated with interaction between the atomizing liquid and its surrounding gas medium. Consequently, the MEP-based distributions show various degrees of discrepancies when compared with various experimental data. In this study, a new model for the droplet size distribution has been developed based on the thermodynamically consistent concept-the maximization of entropy generation during the liquid atomization process. The model prediction compares favorably with the experimentally measured size distribution for droplets produced by an air-blast annular nozzle and near the liquid bulk breakup region. Therefore, the present model can be used to predict the initial droplet size distribution in sprays.