The European Court of Human Rights (ECtHR) is an international court operating in the international legal order. Its judgments are not given direct effect in national law. In this sense we have a system of legal pluralism between international and national law. But the ECtHR has constitutional effects in national law through the weight placed on the Court’s practice by national courts. Therefore, constitutional principles are applicable in the interaction between the ECtHR and national courts. This article discusses the transnational constitutional aspects of the Court, and how this should guide the roles of, respectively, the ECtHR and national courts.