The paper discusses a number of theoretical and methodological issues which arise when professional simultaneous conference interpreting (SI) is studied in light of the basic tenets of the functionalist theory of translation and interpreting (T&I) proposed by Hans J. Vermeer (skopos theory). Based on a multi-level model of SI as a professional course of action the paper applies such functionalist notions as skopos, target culture, target-textual autonomy, and “coherence” to a case study of a three-day technical conference with professional SI between English and German. In essence, it is argued that, on a general conceptual level, modelling SI in the framework of the general functionalist theory of Vermeer serves to bring into focus the crucial translational issues of situation, text, and culture. On the other hand, applying skopos-theoretical concepts to the study of a corpus of authentic professional SI reveals some limitations of the extent to which the general functionalist notions fit the specific practice of SI. [Source: abstract in journal]