The purpose of this article is to provide a specific case study of the contradictory discourses concerning Lao as the national language, as the official language, and as the medium of instruction. Through the diglossia framework or Lao as a touch stone, the article investigates how non-mainstream and ethnic minority students use the national language in comparison to their mother tongues and other languages at schools. The result shows that students often use their mother tongue and other non-national language to negotiate their social positions among the majority and the dominant groups.