In many, if not most cases, the ECtHR relies on its own precedents in interpreting the Convention, but some cases may present the Court with new and difficult questions of interpretation. To answer these, the Court relies on a number of specific principles and methods of interpretation. The Court is guided in its work by several core principles, such as effectiveness, evolutive interpretation and autonomous interpretatio, but these are still relatively abstract in nature and they may not suffice to answer a concrete question of interpretation. For that reason, the Court often also relies on the methods of interpretation as described in the provisions of the Vienna Convention on the Law of Treaties, such as textual interpretation, interpretation in light of the travaux préparatoires and internally harmonising interpretation. This chapter discusses the Court’s use of these three methods. In addition to these methods, the Court has opted for a particular refinement of one of the Vienna Convention’s methods, which is consensus or common ground interpretation. This method and the various sources for the Court’s finding of a consensus are also discussed in this chapter.