In this paper, a detailed model of a Solid Oxide Fuel Cell (SOFC) tube, equipped with a tube-and-shell pre-reformer unit, is presented. Both SOFC tube and pre-reformer are discretized along their axes. Detailed models of the kinetics of the shift and reforming reactions are introduced. Energy, mole and mass balances are performed for each slice of the components under investigation, allowing the calculation of temperature profiles. Friction factors and heat exchange coefficients are calculated by means of experimental correlations. Detailed models are also introduced in order to evaluate SOFC overvoltages. On the basis of this model, temperatures, pressures, chemical compositions and electrical parameters are evaluated for each slice of the two components under investigation. Finally, the influence of the most important design parameters on the performance of the system is investigated.An initial version of this paper was published in July of2006 in the proceedings of ECOS’06, Aghia Pelagia,Crete, Greece.