Much of the work in permeability prediction has so far been done with respect to the in-plane properties. Guided by Darcy's law, the in-plane permeabilities (i.e., Kxx and Kyy) have been well characterized by researchers both experimentally and, to some extents, analytically and numerically. Work on transverse or through thickness permeability, however, has been sparse. Due to the fact that the limited length scale in the through thickness direction of most fiber preforms makes transverse permeability a difficult value to measure experimentally, the objective of the present development is to study the feasibility of applying the methodology proposed by the authors in a previous work for in-plane permeability prediction to the estimation of transverse, as well as the in-plane, permeability of a typical 3-D woven fiber preform. The additional objective of this work is to present a preliminary study on the effects of fiber mat compression on the fiber preform permeability.