Central and Eastern European Candidate countries are involved in negotiations with the EU on the implementation of the Acquis Communautaire in their domestic law. These countries are also preparing themselves for international co-operation in the framework of the Kyoto Protocol. Through this co-operation the Candidate countries will most likely transfer GHG emission reduction credits to other industrialised countries listed in Annex B of the Protocol. This can take place through JI project co-operation and/or International Emissions Trading. This paper argues that the Acquis environmental requirements will in general lead to GHG emission reduction in the Candidate countries, which will reduce the scope for JI in these countries. The extent to which the JI scope will be reduced depends, among others, on the timing of entering the EU and the transitional arrangements between the EU and the Candidates.