The due process of law is a principle that should be applied universally, regardless of race and cultural background, to protect human rights. In order to protect the defendant's right in the criminal procedures, provision of court interpreting service is essential and it plays a critical role in the administration of justice. As to the role of court interpreters, the U.S. courts held that the interpreter is an agent of the defendant acting as a language conduit. In order for a court interpreter to discharge his duty and the statements delivered through interpreters to be admitted as evidence in legal proceedings, there should be a system to ensure quality of professional interpreters who are capable of serving as an impartial linguistic conduit between the defendants and the judiciary in legal forums. Although the need for court interpreters has begun to be recognized in Korea, no formal certification or training program has been established. If a defendant who cannot understand Korean is not provided with effective court interpreting service in a criminal procedure, the principle of due process of law cannot be achieved. This article sets out to examine certain legal concepts relating to the role of court interpreters and also highlights the need for an institutionalized training and certifying program for court interpreters.