The academic community has relied on English as its working language in official settings such as international conferences and publications for a long time. University internationalization has thus fostered the use of English as a language of international communication among students and staff, particularly in face-to-face interaction. This paper explores spoken multiparty interaction among non-native speaker students and teachers engaging in academic discourse (i.e., seminars, group work), and aims at investigating the role of idiomatic language in such settings by examining data drawn from the ELFA (English as a Lingua Franca in Academic Settings) and SELF (Studying in English as a Lingua Franca) corpora, compiled in Helsinki (Mauranen 2003, 2006a, 2006b, 2010; Mauranen et al. 2010). Data analysis focuses on the identification of potential ELF-distinctive patterns involving idiomatic language. The research attempts to determine whether idiomatic items appear as the pivotal elements in problemsolving sequences and to identify other idiom-related communication strategies, as well as describe the social functions they fulfill in cross-cultural academic interactions. Attention is also paid to the issues of idiomatic variation and creativity (Pitzl 2009) as well as unilateral idiomaticity (Seidlhofer 2009), that is, how figurative language may challenge the successful achievement of cross-cultural communicative acts.