An analytical-numerical approach is presented for computing the macroscopic permeability of fibrous porous media taking into account their microstructure. A finite element (FE) based model for viscous, incompressible flow through a regular array of cylinders/fibers is employed for predicting the permeability associated with this type of media. High resolution data, obtained from our simulations, are utilized for validating the commonly used semi-analytical models of drag relations from which the permeability is often derived. The effect of porosity, or volume fraction, on the macroscopic permeability is studied. Also microstructure parameters like particle shape, orientation and unit cell staggered angle are varied. The results are compared with the Carman-Kozeny (CK) equation and the Kozeny factor (often assumed to be constant) dependence on the microstructural parameters is reported and used as an attempt to predict a closed form relation for the permeability in a variety of structures, shapes and wide range of porosities. (C) 2011 Elsevier Ltd. All rights reserved.