In this study, a combination of isothermal and adiabatic reactors is modeled for catalytic naphtha reforming process. The performance of the proposed configuration has been investigated under an Isothermal-Adiabatic condition. In order to operate under an isothermal condition, reactors are fabricated in a furnace, consisting of multi parallel tubes. The furnace consists of two main parts, a non-reaction zone and a reaction zone. The inlet naphtha feed is preheated in the non-reaction section and the chemical reactions take place in the parallel tubes which are packed by catalysts in the reaction section. Results show a remarkable increase in the production rates of aromatic (5.72%) and light ends (8.73%) as well as a slight temperature drop under the isothermal condition by fabricating the first reactor in the furnace. The Isothermal-Adiabatic configuration properly improves the production rate of aromatics (octane number) in naphtha reforming process. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.