The formation, composition, structure, and electrochemical properties of ternary surface complexes between copper(II) and ethylenediaminetetraacetate adsorbed on TiO2 xerogels and on thin-film TiO2 electrodes from solutions of varying pH have been studied by potentiometry, EPR spectroscopy, and electrochemical methods. The results strongly indicate that, in contrast to other organic ligands, B-type ternary surface complexes are formed in this system. The organic ligand forms an isolating layer between the surface of the TiO2 electrode and the redox-active copper ions.