Attorney-Client privilege is an ancient common law concept that protects confidential communications between a client and his/her attorney. It is an essential and pivotal tool to provide the effective assistance of counsel and without it a client would not be confident about the fact that his/her secret will be safe. The Privilege has existed for a very long time in various common law countries as well as some civil law ones as well. In Korea, although it might be quite strange to say, but the Privilege is not provided. Only it can be assumed that the Concept has been embedded. This article is about a recent case of the Supreme Court of Korea where the Court does not acknowledge the Concept due to the fact that the Privilege is not clearly provided in any law. In this case, the defendant was charged with a crime of giving bribery to a person who was soon to be a person in charge of re-constructing a certain district. The Accused committed the Crime in order to gain the right to reconstructing the District as an operating company. Before the Prosecution launched the investigation on such suspicion, the Accused asked his lawyer on this upcoming investigation and the Attorney replied with memorandum noting what the Accused should do when the suspicion becomes something that the Accused needs to tackle with. Later, the Prosecution seized a computer from the Accused and found the Memorandum. The trial court and the appellate court ruled that although the Privilege is not provided with clear provision, it is essential to have such Privilege in order to protect the right to effective assistance of counsel. However, as noted, the Supreme Court decided not to accept such reasoning. The Court reached the same conclusion where the Memorandum is not admissible not because the Privilege bans the usage of such document, but because the rule against hearsay prevents the Prosecution to use the document as a piece of evidence.