The Polish Government’s proposal, submitted in autumn 2017, for a comprehensive reprivatisation bill revived the international discussion on the scope of Polish authorities’ obligations to return property taken during World War II and subsequently by the communist regime. However, many inaccurate and incorrect statements are cited in the discussions, e.g. the argument that the duty of the Polish authorities to carry out restitution is embedded in the European Convention on Human Rights and its Protocol No. 1. This article challenges that claim and analyses the jurisprudence of the Convention’s judicial oversight bodies in cases raising issues of restitution of property taken over in Poland before the accession to both of the above-mentioned international agreements. In the article I argue that there is no legal basis for claiming that there exists a legal obligation upon the Polish State stemming directly from international law – in particular human rights law – to return the property and that the only possibly successful legal claims in this regard are those that can already be derived from the provisions of the Polish law applicable to these kinds of cases. In its latest rulings, issued in 2017–2019, the European Court of Human Rights determined the scope of responsibility incumbent on Polish authorities in this respect.