Argon is recovered from a gas stream comprising the same in admixture with oxygen and nitrogen, by a vacuum swing adsorption (VSA) process wherein the mixed gas is passed through an adsorbent bed having thermodynamic selectivity for adsorption of nitrogen and the unadsorbed portion then passed through a second adsorbent bed having kinetic selectivity for retaining oxygen. Both adsorbent beds are regenerated by vacuum desorption, applied to the first bed for a longer time period than that of the second bed. Further purification of the recovered argon may be carried out, if desired, by catalytic hydrogenation of residual oxygen therein. The mixed gas stream fed to the VSA unit may be that obtained from the crude argon column associated with a cryogenic air separation plant and the waste gas from the VSA unit may be recycled to the main column of the cryogenic air separation plant, thus enhancing argon recovery.