Drawing on research interviews with 43 researchers working across four disciplines in two Nordic countries, this chapter examines the researchers’ perceptions of, and choices related to their mono/multilingual knowledge production and research writing practices. Three discourses were found to be constructed in the interview talk: (a) disciplinary monolingualism, (b) dual monolingualism, and (c) functional epistemic multilingualism. For research writing, most researchers in the study opted for a mono- or bilingual publication strategy, but when doing research, the main determiner in terms of how many and which languages the researchers reported to use was the object of research. The pragmatism associated with the researchers’ language practices may thus be related to both mono- and multilingualism.