This paper provides an analysis of the economic benefits, costs and risks that a fast unilateral euroisation would have for the Central and Eastern European EU accession countries. In doing so, a comprehensive and broad overview of the euroisation debate is presented. The overall conclusion from the analysis is that, at this stage, the economics of a rapid unilateral euroisation are highly ambiguous and probably even harmful for the accession countries. However, there are good reasons to believe that the cost-benefit balance of full monetary integration will turn positive for some accession countries within a few years if sound macroeconomic policies are retained, the Maastricht criteria are fulfilled and structural reforms are carried on further to underpin the sustainability of convergence.