A multistep methodology is developed for the characterization of the pore structure of mesoporous materials from experimental data of mercury intrusion and nitrogen adsorption/desorption. The pore-space geometry is described by the pore- and throat-size distributions and pore-shape factors, while the pore-network topology (connectivity) and spatial pore-size correlations are embedded in suitably selected accessibility functions. Analytical mathematical models of the relevant processes are integrated into numerical codes, developed in the environment of a commercial software package of nonlinear parameter estimation. The methodology is evaluated and calibrated with respect to the well-known parameter values of "theoretical" test materials, and is subsequently applied to the characterization of the pore structure of four samples of porous alumina. (C) 2004 American Institute of Chemical Engineers.