This paper focuses on two questions: what kind of linguistic features the so-called ‘essential information’ possesses, if embedded in the context and whether professional interpreters have group characteristics in distinguishing between essential and secondary information. To answer these questions, an empirical study was conducted in which seven professional interpreters and 77 students were asked to select essential information from two different types of text. Especially carefully examined were focus information (recognizable by Korean focus-markers according to Lee (2000)), predicate and proper names. All in all, the results of the two groups do not differ much from each other, but in details, professional interpreters showed some group-specific features. Interpreters were more inclined to omit deducible information as well as chose discourse markers more often than students. The rate of topic-information was higher for interpreters than it was for students. As for the sentence functional distribution of the essential information, the predicate, object and subject were frequently selected in this order. Based on these results, professional interpreters’ comprehension process – compared to those of non-interpreters – is remodelled.