The present invention relates to a process for removing carbon dioxide and optionally hydrogen sulphide and/or COS from a gas stream containing these compounds by washing the gas with an aqueous washing solution containing water, sulfolane and a secondary or tertiary amine derived from ethanolamine. More particularly the invention relates to the process described above, the process being carried out in the presence of a primary or secondary amine compound in an amount between 0.5 and 15 wt. % based on water, sulfolane and amine. The invention further relates to an absorbent liquid to be used in the above process.