The objectives of this study are (i) to investigate the air void properties and (ii) predict the three-dimensional coefficient of permeability of asphalt mixtures by means of the Lattice Boltzmann Method (LBM). Asphalt mixtures with five different gradations and air voids content ranging from 13.7% to 26% were used in this study. The threedimensional structures of air voids in asphalt mixtures were examined by various parameters and used as inputs for LBM simulations. It was found that the air voids content, Euler number, average void diameter, tortuosity, and degree of anisotropy were highly correlated to the coefficients of permeability. In addition, the permeability values predicted by LBM had a significant correlation to the laboratory measurements for all the range of mixtures studied. It was concluded that the air void structures in the horizontal directions were equivalent and, in addition, they differed from those in the vertical direction. (V) 2020 Elsevier B.V. All rights reserved.