As a state of law, Indonesia has positive laws governing brands. Well-known brand owners to the new are entitled to equal protection under the law. But in the protection of brand owners there are still some problems that derogate intellectual property rights to brand owners in Indonesia. One of the problems that are prevalent is bad faith in brand registration. Brand registration based on bad faith has harmed the original brand owner, and damaged the market in the community. This study will examine the root causes of bad faith arrangements in Law Number 20 of 2016 concerning Trademarks and Geographical Indications. Apart from the perspective of the law, the study will be carried out through the implementation of bad faith arrangements in the case study of the Supreme Court Decision Number 938 K / Pdt.Sus-HKI / 2017. This study uses a normative juridical type equipped with a case approach. The material used in this study adapted from library sources. In addition to the central sources there are also material from related decisions from the Commercial Court level to the Supreme Court. Generally bad faith in brand registration can be interpreted as a way to piggyback on brands of other more famous people. The definition of bad faith is regulated in Article 21 paragraph (3) of Law Number 20 of 2016 concerning Trademarks and Geographical Indications. In the explanation of the article there is further exposure even though the concrete meaning is still difficult to explain. Procedurally, brands that register in bad faith can be cancelled or deleted. In the case of HUGO BOSS against ZEGOBOSS it was found that the difference between the two brands was weak and that it was in bad faith. Seeing the existence of a bad faith owned by the defendant because of the similarities in the principal and the whole towards the plaintiff as a well-known brand, the registration of the defendant's trademark must be cancelled.