As the significance of the patent grows sharply in the modern society, the number of patent litigations is also on the rise. The defense based on patent misuse is often raised in the patent infringement litigations. In Korea, this defense is based on the Article 2 of the Korean Civil Code in which the principle of good faith and the prohibition of the abuse of right is stipulated. This is due to the fact that there is no explicit provision on patent abuse in Korea. The doctrine of the abuse of right has been applied to various types of litigations, in particular to the land ownership related cases. One noteworthy trend in a series of relevant court decisions is that the courts tend to emphasize the subjective requirement, that is an intention to harm the defendant. However, this doctrine in its original context has seldom been used in the patent litigations. Rather, the Korean Supreme Court has applied this doctrine in order to reject a patent lawsuit based on the seemingly invalid patent. According to the Korean patent regime, the general courts adjudicating patent infringement lawsuits are not allowed to declare the invalidity of patent. The power of declaring the patent invalid is solely given to the Patent Office. However, the Supreme Court has used the doctrine of right of abuse as one of the vehicles that helps the court bypass this hurdle, thereby entitling the general courts to adjudicate cases based on its own judgment on the invalidity of patent. According to the Supreme Court, exercising the patent which has defects that will evidently render the patent invalid in the future is deemed patent misuse. Considering that patent misuse rests on the idea that patent should not be given broader protection than it deserves, this article went on to touch upon related issues, such as the flexibility in ordering an injunction as is shown in the famous ebay case in the U.S. Supreme Court, the requirement of "the necessity to order a preliminary injunction" in the preliminary injunction procedure in Korea, and the antitrust concerns in determining the patent misuse defense.