An overview is given of different methods of modern computational chemistry, with emphasis on how, in combination with experiment, the results of such simulations may enhance our understanding of electrochemical and electrocatalytic processes on the molecular level. Recent developments in modeling electrode reactions using Marcus theory and molecular dynamics simulations include treatment of electrode reactions in which bonds with the surface or within the reacting molecule are broken or formed. First-principles electronic structure calculations based on density-functional theory allow the accurate calculation of binding energies and vibrational properties, which are of much interest in comparison with experiment. Inclusion of electric field effects and water in these state-of-the-art simulations also yield unique insight into the properties of the electrochemical interface on the molecular level, and this is certainly a field in which there will be much progress in the not too distant future. Finally, kinetic modeling using "meanfield" equations or Monte Carlo simulations, preferably combined with input or insight from first-principles calculations, produce voltammetric and chronoamperometric responses, which may be compared to experiment. (C) 2004 Elsevier B.V. All rights reserved.