A 3D realistic numerical model of the electrostatic coating process has been developed including all relevant mechanical and electrical phenomena. The commercial computational fluid dynamics (CFD) software FLUENT was used to simulate the mechanical portion of the process. The electrical phenomena including space charge fields due to ions and poly-disperse particle charge distributions were added to FLUENT through the User Defined Function (UDF) capabilities. Selected example results are shown to demonstrate the effect of particle charge to mass ratio distributions, electrohydrodynamic flow effects and corona currents on particle trajectories and deposition efficiency. These numerical results correlate well with the theoretical expectations for static targets. In addition, an efficient method for handling 3D cases with moving flat parts is presented using the superposition principle. A procedure for extending the model for the general case of 3D moving targets is suggested.