This Article provides the first in-depth analysis of the use of foreign authorities to resolve issues related to domestic statutes, particularly focusing on intellectual property (IP) statutes. The study of IP statutes provides a fertile area of research because of the increased pressures for international protection of IP. The Article criticizes the current approach U.S. courts have taken to using foreign authorities in this area, which can best be described as ad hoc. The Article then sets forth a framework by which U.S. courts can decide, more systematically, when to rely on foreign authorities in IP cases. The Article fills a major gap in the current debate over the use of foreign authorities in domestic cases. Most of the recent contributions on this controversial subject from legal scholars, lawmakers, and Supreme Court justices have been fixated on constitutional law. It is at least as important, however, to ask whether U.S. courts may rely on foreign authorities in resolving claims arising under domestic statutes. This Article aims to answer that question for the field of intellectual property, where citations to foreign authorities are becoming more frequent.