Almost a year following the third “eastern” enlargement of the European Union (EU) and first to the Western Balkans (Croatia), one particular research question remains unanswered: why does EU conditionality, which proved to be the main attraction and strategic tool leading to EU accession in the post-communist countries, still find hostile ground in most of the Western Balkan states? The thesis believes this dilemma deserve re-orientation of the existing academic research regarding EU conditionality as a mechanism of Europeanization. The thesis suggests that in all the countries of the Western Balkans, including Croatia as a new EU member state a huge gap exists between ‘rule transfer and ‘rule diffusion; hence, the research hypothesises the inadequacy, to a large extent, of the EUs ‘external governance method to the mentioned states, which consisted of applying EU conditionality based on the pre-dominance of ‘external incentive model as conceptualised by the mainstream Europeanization theory. Contrary to the majority of relatively new scholarship, the present doctoral thesis in this regard does not focus on either the EU conditionality or Balkan complexity as a unique explanation for the ineffectiveness of EU rule transfer. Instead, it complements the existing literature by emphasising how the mutual interaction of both concepts influences patterns of compliance in the selected cases, thus identifying and re-constructing factors to the positive fulfilment of conditions. The thesis key argument therefore posits that the EU can ‘accommodate its conditionality approach to the Western Balkans by carefully balancing between the domestic contextual constraints and setting of the conditions. Otherwise, the concept of EU conditionality and its methodology can hardly continue to be justified and may even become counterproductive, as some authors already suggest.