A pseudo-homogeneous model. predicts that a stationary, stable, transversal nonuniform temperature pattern cannot form in any cross section of an adiabatic packed-bed reactor used to conduct a single reaction, if its dynamics depends only on the concentration of a limiting reactant and temperature. This is due to the fact that the transversal heat dispersion in the reactor is larger than that of the limiting reactant. This conclusion is proved for a shallow packed-bed reactor described by a pseudo-homogeneous model. Extensive numerical simulations showed that a two-phase model of an adiabatic packed-bed reactor exhibits the same behavioral features. A stable, stationary hot zone can form in the cross section of the reactor only under the unrealistic assumption that the transversal species dispersion exceeded that of the temperature. (c) 2005 American Institute of Chemical Engineers.