The Dublin Regulation establishes criteria and mechanisms for determining the Member State responsible for examining an application for asylum lodged in the European Union by a third-country national. The system is based on the presumption that Member States may be considered ‘safe countries’ for asylum seekers, for which reason transfers from one Member State to another are supposed not to violate the principle of non-refoulement. The fact that all Member States have acceded to the 1951 Refugee Convention and to the European Convention on Human Rights, that they share a pledge to establish a Common European Asylum System comprising harmonized protection standards, and that, as members of the Union, are obliged to respect and protect fundamental rights, constitute the unspoken premises on which the supposition rests. However, the Dublin Regulation does not establish whether the presumption should be considered absolute or rebuttable, and how and when, in the latter situation, it should be deemed refuted in the individual case. How the ‘principle of refutability’ has come into being in the case law of the European Court of Human Rights constitutes the focus of the present analysis. The review of the Strasbourg jurisprudence is accompanied by an assessment of the diverging practices that have proliferated across the EU in this regard. The paper concludes with some reflections on the impact of the M.S.S. judgement on the forthcoming reform of the Dublin system.