As a result of the increase in trade over intellectual property (IP)-related goods, the risk of encountering intellectual property rights (IPRs) infringement occurs. When a third party’s IPRs are infringed, the buyer of such goods can be prevented from using or reselling the goods in question according to IP law. Article 42 of the United Nations Convention on Contracts for the International Sale of Goods (CISG) covers these situations and obliges the seller to ‘deliver goods which are free from any right or claim of a third party based on industrial property or other intellectual property’. However, there is no definition of ‘industrial property or other intellectual property’ either within the wording of Article 42 or the scope of the CISG. This chapter questions whether the international IP agreements and IP rules of domestic law where the claim is raised should be applied in Art 42 CISG cases to examine the existence of third-party IPRs over the goods purchased by the buyer. Although the CISG should be interpreted regarding its international character, I argue that any IPRs or claims should be examined according to the law under which the right or claim has been raised.