Lexical bundles, as “building blocks of discourse” (Biber & Barbieri 2007: 263), vary across disciplines and genres. Mastery of lexical bundles signals professionalism and helps identify writers and speakers as members of specific discourse communities. Despite the contribution of lexical bundle research to our understanding of disciplinary variation, the constraints placed by the genre conventions of quantitative, qualitative, and mixed-methods approaches to research writing on the use of lexical bundles remain under-researched (Le & Harrington 2015). This study aims to explore the extent to which quantitative, qualitative, and mixed methods research articles are similar or different with respect to the frequency and functional patterns of their lexical bundles. Towards answering this question, however tentatively, the present exploratory study reports on the extent to which lexical bundles function similarly or differently in the discussion sections of quantitative, qualitative, and mixed-methods research articles in the field of applied linguistics. A corpus-based analysis of discussion sections in 150 research articles culled from ten highly rated international journals in the field of applied linguistics suggest that at the level of discussion sections, different methodological paradigms are characterized by different functional uses of lexical bundles. These lexical bundles are sufficiently formulaic that it can be argued that they constrain writers’ language preferences. These findings may be of interest to applied linguists, second language educators and advanced learners of academic English.