Stille coupling reactions are one of the most common coupling reactions used nowadays. For many years only phosphorous ligands have been considered in the catalysts for this type of reaction but recent studies have shown that also arsenic ligands are very promising. In this study, DFT calculations were applied to the Stille coupling reaction of different systems (with various substrates and catalysts) in order to obtain the energy values associated to the various steps of the reaction. In trial 1, oxidative addition was found to be a rate-determining step (but the considered halogen atom could effectively modulate the energy levels of this step), while transmetalation was found to be a rate-determining step only with phosphorous ligands.