Our recent research has found that structured preoperative team briefings can reduce communication failures, improve the knowledge and practice of operating room (OR) team members, and garner broad support from surgeons, nurses, and anesthesiologists. However, we have also encountered challenges and unexpected, negative effects. Using qualitative analysis of fieldnotes from 302 preoperative team briefings, we identified five paradoxical findings: team briefings could mask knowledge gaps, disrupt positive communication, reinforce professional divisions, create tension, and perpetuate a problematic culture. Fifteen percent of the briefings exhibited only these paradoxical effects without any apparent utility. We describe these paradoxical findings and analyze them in relation to educational, functional, structural, and cultural factors. This analysis is instructive not only for re-engineering the briefing process, but also for revealing dynamics that may continue to impede optimal interprofessional performance.