An analytical and numerical investigation is conducted to study the effect of an electromagnetic field on natural convection in a vertical rectangular porous cavity saturated with an electrically conducting binary mixture. Uniform heat fluxes are applied to the vertical walls while the horizontal walls are adiabatic. Governing parameters of the problem under study are the thermal Rayleigh R T , Hartmann number Ha, buoyancy ratio phi, Lewis number Le, and aspect ratio A. An analytical solution, valid for tall enclosures (A > > 1), is derived on the basis of the parallel flow approximation. In the range of the governing parameters considered in this study, a good agreement is found between the analytical predictions and the numerical results obtained by solving the full governing equations.