Research on EU enlargement-led Europeanisation has extensively focused on countries from Central Eastern Europe (CEE) and only recently enriched with studies dealing with specific issues and/or countries of the Western Balkans. Yet, a more comprehensive study across current and previous potential member-state countries is needed. This article assesses to what extent EU candidate countries from Eastern Europe have been able to bring their policies and institutions – both in formal and practical terms – in line with EU requirements. By tracing the progress of all countries from Eastern Europe (1998-2012) this work shows Europeanisation asymmetry among enlargement rounds. This work argues that “EU membership credibility” is an important factor in EU enlargement-led Europeanisation performance.