Nitrogen physisorption on mesoporous carbonaceous materials is studied through Monte Carlo computer simulations. Bernal’s model is employed to describe the solid. Several pore geometries are generated. The resulting pores also present amorphous walls. Grand canonical and canonical ensembles are employed to obtain the adsorption isotherms and the configurations of the adsorbed molecules at different surface coverages. The distributions of molecules with respect to the gas-solid and gas-gas interaction energies, the microdensity profiles as a function of the distance to the surface, and the local density of the adsorbed phase as a function of the surface coverage are discussed.