The redox potential of the Ag-1(I)(CN)(2)(-)/Ag-1(0)(CN)(2)(2-) couple in aqueous solution is evaluated with the aid of a thermodynamical cycle including gas phase and solvated species. We use the SCF method for the determination of the electronic structure of the gaseous species and the cavity model for the solvation effect. We find the value -2.6 V/NHE, which is lower than the value (-1.8 V) relative to the Ag+/Ag-0 couple and hence much lower than the value (+0.8 V) relative to the hulk metal.