The right to a fair trial, a fundamental right, has long been regarded essential to protect other human rights. It has been codified in treaties in international human rights law and international criminal law, making it almost universal right in international law. Attempting to analyze the application and interpretation of the right in practice, this article focuses on the rulings of the European Patent Office Board of Appeals mainly because they recognize the limitation of the right while its absolute nature was affirmed. By analyzing the relevant regulations and rulings (or, legislative practice and jurisprudence), this article explores its implications (for international law) by focusing on the main findings of the jurisprudence and whether the right was violated. Finally, this article suggests introducing the interim procedure found in the Agreement on the Unified Patent Court as a means to provide European patent proprietors with more opportunities to make their cases orally.