Cell sorting is a fundamental process that is involved in early embryo development, tumerogenesis and morphogenesis. The sorting of heterotypic cell populations is produced by a variety of inter-cellular actions, e.g. differential adhesion and motility. We recently developed a software system that simulates chemotaxis-based cell aggregation in 2D. The model implemented within the system includes a variety of physiological cell behaviors, such as chemical diffusion/detection, motility, proliferation, adhesion and life cycle stages. In this paper we extend the model to simulate heterotypic cell sorting. This paper provides an overview of the chemotaxis-based aggregation model and describes the parameters and processes utilized to simulate the sorting of two different cell populations based on chemotactic interactions.