This article illustrates an intermodal study on simultaneous interpreting and translation from Italian into English based primarily on the European Parliament Interpreting Corpus (EPIC) and ofﬁcial translations from the European Parliament. In line with Gideon Toury’s posited law of interference, the hypothesis that drives the present study is that interpreters and translators working into English from Italian may underrepresent the ’s-genitive as a result of the syntactic asymmetry between English (which alternates between ’s and of) and Italian (which only has one type of prepositional phrase consisting of di + noun). The results of this study indicate that ’s-genitives occur with lower frequency in interpreted English than in non-mediated English, thus revealing a particular form of syntactic interference. The same tendency, however, is not found in translations from Italian into English. This difference is explained by recourse to Englund Dimitrova’s (2005) ﬁndings on translation expertise and to the literal translation hypothesis (Chesterman 2011) and by suggesting that simultaneous interpreting tends to adhere to the source-language syntax more closely than translation, thus displaying similarities with translation drafts. The results also point to the theoretical and methodological limitations of the théorie du sens developed by the Paris School of Interpreters and Translators.