During the summers of 1952 and 1953, Emile Benveniste, at that time one of the leading figures in the fields of Indo-european and general linguistics, undertook linguistic investigations on the Haida and Tlingit languages, but also on Gwich’in, Tutchone and Inupiaq, at various locations in the Pacific Northwest. The notes he compiled have not yet been studied or published. This presentation will focus on Benveniste’s work on Tlingit. We’ll try to explain shortly the context of his research (his growing interest in American linguistics and American languages), we’ll present the linguistic and ethnographic materials available at this time on Tlingit, and then the notes and fiedlnotes Benveniste took in 1953. During the month of July 1953 Benveniste worked with 5 different informers ; we’ll analyse his fieldwork method (for example the constant use and discussion of Franz Boas’ grammar), and try to show which aspects of the language retain his attention. During the academic year 1953-1954 Benveniste gave a course at the Collège de France on the languages of the Pacific Northwest : we’ll see that most of the classes were dedicated to the description of Tlingit, and in particular to the problem of the verb.