Trademark is a sign that can be displayed graphically in the form of images, logos, names, words, letters, numbers, arrangement of colors, in 2 (two) dimensions and/or 3 (three) dimensional forms, sounds, holograms, or a combination of 2 (two) or more elements mentioned to differentiate goods and/or services produced by individuals or legal entities in trading activities of goods and/or services. Protection regarding trademark is regulated in the law of the Republic of Indonesia Number 20 Year 2016 pertaining to brand and geographic indication. This protection is fundamental because trademark constitute to a part of an intellectual work that is based on the existence of natural rights that arises to someone who has spent thoughts, time and cost in the process of creating a brand. In practice, the act of cheating or unfair business competition frequently appears, it arises when there is a product trademark, whether in the form of certain goods or services, which is well known and salable in the market beforehand, so it tends to make other producers or entrepreneurs spur their products to compete with that brand. This research has a formulation of the problem regarding: how is the legal protection of a registered trademark in Indonesia if the trademark is registered in bad faith and what is the basis for legal considerations from the Panel of Judges at the Cassation level in deciding disputes over the EIGER Mark, class 25, in the Supreme Court Decision Number 375 K / Pdt.Sus.HKI / 2020. The purpose of this research is to identify and understand the legal protection of trademark registered in Indonesia if the trademark is registered in bad faith, and to analyze the legal considerations of the Panel of Judges at the Cassation level in deciding disputes over the EIGER Mark, class 25, in the Supreme Court Decision Number 375. K / Pdt.Sus.HKI / 2020. In the first lawsuit at the Central Jakarta District Court number 41 / Pdt.Sus-Mark / 2019 / PN.Niaga.Jkt. Pst. Ronny Lukito sued Budiman Tjoh regarding the registration of the Eiger mark which was registered in bad faith. The lawsuit at the first level was won by the Plaintiff or Ronny Lukito. Then Budiman Tjoh again filed a cassation lawsuit with registration number Number 375 K / Pdt.Sus.HKI / 2020 to the Supreme Court