We develop an analytic solution of the Maxwell-Stefan equations describing steady-state diffusion of n-component mixtures across a zeolite membrane. In the development of the analytic solution we assume Langmuirian behaviour of the pure components and that the mixture sorption can be calculated from the multicomponent Langmuir isotherm. Explicit expressions are derived for calculation of steady-state fluxes and the loading profiles in the membrane. The utility of the developed solution is illustrated by means of two illustrative examples involving permeation of alkane mixtures across an MFI membrane. (C) 2003 Elsevier B.V. All rights reserved.