CO adsorption and desorption rates and adsorption equilibrium coefficients are analyzed for the processes on the close-packed metal surfaces of ruthenium, iridium, palladium, rhodium, and platinum assuming the adsorption to be activationless and using mobile and immobile adsorption layer models. Parameters required for calculations of the CO adsorption isotherm on these surfaces were studied using the CO initio density functional theory (DFT) cluster method with two correlation-exchange functionals. The adsorption energies, adsorption lengths, and metal-CO vibrational frequencies in the metal series were computed for two types of the adsorption sites, the on-top and the hollow hep (hexagonal close-packed). Results of the calculations are compared with those obtained in other theoretical works and with experimental data. The application of the obtained results for catalysis is discussed.