This article questions whether the law of the European Union (EU) can impose jurisdictional constraints on so-called intra-EU investment arbitration proceedings. Would an arbitral tribunal hearing an intra-EU case under either a bilateral investment treaty (BIT) or under the Energy Charter Treaty (ECT) have to declare itself incompetent to conduct the case proceedings owing to the operation of EU law? This article subjects that proposition to criticism, finding that, for a number of reasons, connected either with the drafting of the BIT or the ECT or the operation of general principles of international law, it does not withstand scrutiny. An arbitral tribunal seized of a treaty claim under a BIT or the ECT cannot rely on EU law to negate rights expressly granted under the instrument providing for its jurisdiction.