Vicente, Marta Nunes2021-07-122021-07-1220200866-9449http://hdl.handle.net/10400.14/34128The present article aims to critically describe and compare how two rather different legal fora*the United States Supreme Court and the European Court of Human Rights*address the same constitutional issue: the protection of property rights and legitimate expectations in the face of a legal change. According to the US Federal Constitution, the effects of a legal change over patrimonial interests can be treated under the due process of law clause or the takings clause. Article 1 of Protocol No. 1 of the European Convention on Human Rights, alone or in conjunction with the right to a fair trial, plays the same role under the ECHR. Our concluding remarks will show that in both systems, property protection provisions amount to a guarantee against unfair governmental action. Regulatory takings and proportionality are areas of strong disagreement between the two systems, whereas retroactive legislation and patrimonial expectations reveal some interesting similarities.engEuropean Convention on Human RightsExpropriationLegitimate expectationsPropertyUnited States Federal Constitutionjournal article10.12775/CLR.2020.00285101637893