At the heart of safe cultures are effective interactions within and between interprofessional teams. Critical care clinicians see severely ill patients who require coordinated interprofessional care. In this scoping review, we asked: "What do we know about processes, relationships, organizational and contextual factors that shape the ability of clinicians to deliver interprofessional care in adult ICUs?" Using the 5-stage process established by Levac et al. (2010), we reviewed 981 abstracts to identify ethnographic articles that shed light on interprofessional care in the intensive care unit. The quality of selected articles is assessed using best practices in ethnographic research; their main insights evaluated in light of an interprofessional framework developed by Reeves et al (Interprofessional Teamwork for Health and Social Care. San Francisco, CA: Wiley-Blackwell; 2010). Overall, studies were of mixed quality, with an average (SD) score of 5.8 out of 10 (1.77). Insights into intensive care unit cultures include the importance of paying attention to workflow, the nefarious impact of hierarchical relationships, the mixed responses to protocols imposed from the top down, and a general undertheorization of sex and race. This review highlights several lessons for safe cultures and argues that more needs to be known about the context of critical care if quality and safety interventions are to succeed.