Three-dimensional site-bond-site network modeling was applied to simulate the deactivation process of three types of zeolites: BEA, FAU and MFI. A simple process rate model was used to describe the deactivation in terms of relative activity while a detailed Monte-Carlo reaction model was used to study the coke formation, including adsorption, desorption, reaction and diffusion effects. The simulation results were compared with experimental data for coke formation. The study shows the importance of catalyst morphology and topology described in the present model by measurable parameters like: connectivity of network and size distribution of cavities and channels. The present model correlates effectively the available experimental deactivation data for the cases studied, both for short or long times of reaction, showing the importance of taking the pore structure into account when modeling catalyst deactivation. (C) 2004 Elsevier B.V. All rights reserved.