The Central and East European (CEE) countries that had applied for membership in the European Union were confronted with far-reaching requirements in order to bring domestic policies in line with EU standards. Notwithstanding these rather uniform pressures emerging from conditionality, there is considerable variety in alignment performance across the candidate countries and over time. To account for this, we use time series cross-sectional data on the implementation performance of 13 EU candidate countries between 1999 and 2003. Our results indicate that the bureaucratic strength and effectiveness of a country positively influence its ability to adjust domestic arrangements to EU requirements. By contrast, we find no support for veto-player theories of political constraints on legislative change. We hence conclude that the implementation of the acquis communautaire in candidate countries prior to accession has been a question of bureaucratic problems rather than of political veto-manoeuvres.