Ionic liquids have been under intensive investigation since 1999 as solvents for the separation of carbon dioxide from gas streams. Recent developments have included the evaluation of their performance in mixtures of amines and water and the development of Task-Specific Ionic Liquids which involve the attachment of amine moieties to ionic liquids for improved performance in specific applications. Now work is focused on the development of process designs to enable their incorporation and implementation as part of large scale facilities. This paper provides a review of the use of ionic liquids for the separation of carbon dioxide from gas streams.