In this work we present an application of the lambdaphi(4) field theoretical model to the adsorption of atoms and molecules on metallic surfaces-the electrochemical deposition. The usual approach to this system consists in the computational simulation using Monte Carlo techniques of an effective lattice-gas Hamiltonian. We construct an effective model towards a comparison between the lattice-gas Hamiltonian and the discrete version of the lambdaphi(4) Hamiltonian, obtaining the relationships between the model parameters and electrochemical quantities. The lambdaphi(4) model is studied in the mean field approximation, and the results are fitted and compared to numerical simulated and experimental data. (C) 2004 American Institute of Physics.