This study investigated relationships between students’ cultural orientations and the ways in which they communicated with their peers in collaborative online discussions. 211 undergraduate business students from diverse backgrounds completed questionnaires directly assessing their cultural orientations along four dimensions (individualism, collectivism, power-distance and cultural-context). Scales were input into mixed multi-level models to predict 12 aspects of the way students communicated in their course-based collaborative discussions of business cases. Results based on a sample of 1565 posts showed that students with weaker context-based orientations posted messages that showed greater levels of reasoning, hard evidence use, autonomous tone and linear argument structures. In addition, the local discussion group context moderated the relationship between students’ degree of collectivistic orientation and how they referred to and agreed with each other, as well as their expressions of social presence. Findings highlight the group/individual interplay in understanding relationships between cultural orientations and collaborative communication.