This paper analyses the negotiations which will take place with the six Western Balkan countries (Albania, Bosnia & Herzogovina, Croatia, the former Yugoslav Republic of Macedonia, Montenegro and Serbia) and attempts to identify where the major problems are likely to lie. The experience of the fifth enlargement of the European Union to the 12 countries of Central and Eastern Europe is used extensively in this analysis for two reasons: firstly, because the offer made to these countries is likely to be the starting point for the offer to be made to the countries of the Western Balkans; secondly, because the problems which occurred in the negotiations for the fifth enlargement are likely to be the main areas of negotiation with the six countries.