This chapter examines interlanguage lexico-semantic interference in the legal translation classroom. Drawing on extensive research in applied linguistics, the author employs a methodology focusing on various linguistic phenomena that potentially have a negative interference effect at the lexical and semantic levels. The analysis, based on a contrastive examination of English and Russian legal terms and frequently used lexis of legal texts, highlights three types of false cognates: synonymous, contact, and distant, and their subtypes in the given legal contexts. Moreover, such linguistic phenomena as polysemy, homonymy, paronymy, and synonymy are considered as additional interference triggers. The findings guide recommendations for teaching strategies in English-Russian legal translation courses, aiming to minimize negative interference from the learners’ native language. The chapter concludes with practical classroom suggestions for exercises designed to enhance comprehension and the application of legal vocabulary for translation purposes in both English for specific purposes, and more general English as a Second/Foreign Language contexts around the world.