Food pasteurization can be defined as a thermal or non-thermal process that brings about microbial inactivation and extends the shelf life of a food product. Thermal pasteurization can be explained with a comprehensive understanding of the temperature distribution within the product during the heat treatment. However, a real-time study of the temperature profile within the product is tedious as it is an unsteady state problem and involves various complexities including irregularly shaped geometries. Similarly, with a non-thermal pasteurization process such as the high intensity pulsed electric field processing (PEF), prediction of the distribution of electrical field strength within the treatment chamber is difficult owing to the extremely short processing times. With respect to food pasteurization processes, the capabilities of CFD modeling include prediction of temperature profiles, microbial inactivation kinetics and determination of the slowest heating zone inside the product; aiding the optimization of process variables and the design of equipment. This chapter presents the methodology and applications of CFD modeling pertaining to the pasteurization for different food products by thermal and non-thermal techniques.