<p>Existing empirical studies in first language contexts have demonstrated that Lipman’s community of inquiry (CoI) approach fosters students’ critical thinking, creative thinking, communication, and collaboration. However, its impact in English as a foreign language (EFL) settings remains underexplored. This study addresses this gap by investigating how integrating the CoI approach in an EFL university classroom affects students’ discussion performance, particularly in terms of participation, interaction, and cognition. Fifteen second-year EFL students participated in an eleven-week intervention, during which seven hours of video from eleven CoI discussions were collected. Content analysis of the discussion transcripts focused on turn-taking, interaction patterns, and cognitive depth. The findings revealed that students’ turn-taking percentage increased from 66.70% to 75.90% and that the spoken word percentage grew from 60.80% to 84.80%. Later CoI discussions featured more synergistic interactions and deeper cognitive engagement. Specifically, basic ‘exploration’ decreased by more than half, whereas in-depth ‘integration’ increased by a similar degree by the end of the intervention. An intimate relationship between in-depth cognition and synergistic interaction also emerged. These findings suggest that the CoI approach can potentially increase EFL students’ participation, interaction, and cognition, offering pedagogical, theoretical, and methodological implications for teachers and researchers in China and comparable contexts. The limitations of this study are acknowledged, and suggestions for future research are provided.</p>