Wall deposition of charged particles in a turbulent duct flow in the presence of electrostatic charges is studied. The turbulent flow velocity field is generated by a direct numerical simulation of the Navier-Stokes equation via a pseudospectral method. It is assumed that the particles are sufficiently small and widely separated that they do not interact and have no influence on the fluid motion.The equation of motion of particles including the Brownian and electrostatic forces is used in the analysis. Ensembles of 8192 charged particle trajectories are evaluated and statistically analyzed. Uniform and Boltzmann charge distributions on the particles are considered. Effects of size and electric field intensity on particle dispersion and wall deposition rate are studied. The results are compared with those obtained from empirical equations.