A theoretical description of multilayer adsorbate film flow, consistent with the simple multilayer adsorption theory in common use, is derived on the basis of the simple pore model previously used by Flood et al. (Can. J. Chem. 1952, 30, 389). The resulting expression clearly supersedes the earlier one of Flood et al. (Can. J. Chem. 1952, 30, 389), both on theoretical grounds and from the point of view of successful interpretation of the surface flow behavior exhibited by a typical mesoporous adsorbent/permeating vapor system in the multilayer adsorption/condensation region.