This thesis discusses the passing off problems in Indonesia. Brand is a company asset that is priceless, especially for well-known mark. The purpose of this study to determine the application Trademark Law applies in case the verdict between DIOR and BABY DIOR. It aims legal certainty for famous brand protection so there will no unfair competition. This thesis also aims to see any legal considerations on which the registration of the mark in the Indonesian judiciary. Based on the research I concluded that Law contains regulations concerning passing off mark, but the Supreme Court's decision not in accordance with Law No. 15 of 2001 on Trademarks, the Paris Convention, and the TRIP's Agreement. Indonesia needs better law enforcement system and this is possible in the can through stricter sanctions which can be given to the guilty parties.