The kinetics of catalyst deactivation by coke formation are modeled at the micro, meso- and macro-level. The deactivation mechanisms considered at the micro-level are the coverage of single sites and of clusters of sites by undesired side reactions. At the meso-level blockage and diffusion limitations in single pores and networks of pores have to be accounted for. At the macro-level these mechanisms and their kinetics are combined with those of the main reactions and transport phenomena at the reactor scale. Processes dealt with are steam reforming of natural gas; methanol-to-olefins on ZSM5; solid acid alkylation; styrene production from ethylbenzene and catalytic cracking of heavy oil fractions