A Monte Carlo simulation of electrochemical electron transfer (ET) is performed at small overpotentials with the use of the Dogonadze, Kuznetsov and Vorotyntsev model (J. Electroanal. Chem. 25 (1970) App. 17). The ET process is considered as a random walk in a set of Gibbs energy surfaces (GES) corresponding to various electronic states. The method allows one to calculate the transition probability at arbitrary electronic coupling of the redox couple with the metal electrode, i.e. it covers the whole range between non-adiabatic and adiabatic limits.