CONTEXT In the clinical environment, health care professionals self-categorise into different groups towards which they develop positive attitudes, whereas they view other groups less favourably. Social identity theory purports that these attitudes influence group processes and may foster conflicts that impede collaborative practice, although this relationship is poorly understood. This study used concepts from social identity theory to examine the interplay between group processes and conflicts, as well as the consequences of these conflicts, with the goal of identifying educational strategies to favour teamwork. METHODS Semi-structured interviews with 82 randomly selected physicians and nursing professionals working at a Swiss academic medical centre explored participants' experiences of conflicts. Data analysis was informed by social identity theory and focused on interviews where group processes were highlighted by participants. The analysis sought to uncover how group processes were intertwined with conflicts and how they affected health care professionals. RESULTS A total of 42 participants out of the initial pool of 82 interviews shared 52 stories of conflicts involving group processes. Most of these stories were shared by physicians and involved groups of physicians at different hierarchical levels. Conflicts and group processes were linked in two ways: (i) through processes of group membership when individuals struggled to join a relevant group, and (ii) through intergroup boundaries, such as when participants perceived that power differentials disadvantaged their own groups. Conflicts could lead to difficult experiences for clinicians who questioned their abilities, became disillusioned with their professional ideals and developed negative perceptions of other groups. CONCLUSIONS This study suggests that conflicts involving group processes may lead to stronger intergroup boundaries, challenging current educational efforts to favour teamwork in health care. Taking steps to create more inclusive groups and to encourage perspective taking may help manage intergroup conflict.