Traditionally, nationality is considered to fall within a domain of legal competence reserved to internal law. Nationality lies at the very heart of the concept of a State because its function is to define the body of citizens of a country, wich is an essential element of State sovereignty. For this reason, traditionally, in international law provisions there have been very few limitations on State powers in nationality matters. Nevertheless, the extraordinary development of international law during the 20th century and the implementation of the international protection of human rights bring into question this traditional assumption because they show that rules and case law at the international level are able to get in the legal bond between an individual and a home country, also constraining State autonomy in nationality rules. In Europe, this matter has been studied especially with regard to European Union legal order because the European Court of Justice has enlarged the number of public social services that cannot be restricted to National citizens by a large interpretation of European citizenship and the non-discrimination principle, and also because it has indicated that there may be some limits for Member States when regulating their nationality laws. Lacking attention has received the impact of European Court of Human Rights case law in the State nationality matter. This paper aims to examine if the European system of the protection of human rights can bring about rules and legal principles having an impact on the State nationality laws and constraining State autonomy in this particular field.