The diffusion and adsorption parameter values of tritium in palladium-silver cathodic membranes used to produce pure tritium gas and its isotopes from highly concentrated tritiated water are determined. It is shown that permeation increases with applied cathodic potential, temperature, and the presence of a palladium black deposit on the cathodic entry surface. The diffusion coefficient, tritium concentration in the alloy, and the diffusion layer thickness depend on temperature. The presence of a palladium black deposit on the palladium-silver membrane improves the adsorption of tritium.