Introduction: Intrahospital transport (IHT) of critically ill patients for magnetic resonance (MR) imaging is a high-risk procedure that combines physiological vulnerability with MR-specific hazards. While technical guidelines and checklists exist, less is known about how MR safety is accomplished in everyday clinical practice when critically ill patients undergo MR imaging. This study aimed to explore how MR safety is enacted during IHT. Methods: A multisite focused ethnographic design was employed. Fourteen in-person observations were conducted across eight hospitals in Sweden and Portugal. Observations followed critically ill patients from ICU preparation through transport, MR scanning, and return to the ICU. Data consisted of field notes and analysis was conducted using inductive thematic analysis. Results: MR safety emerged as a dynamic, context-dependent accomplishment rather than a fixed protocol. Three themes were identified: (1) the use of written, mental, and visual checklists and timeout procedures to coordinate safety work; (2) adaptation to spatial configurations and zoning practices shaping workflows and risk boundaries; and (3) managing uncertainty related to implants, devices, and incomplete information. Safety was continuously negotiated through interprofessional collaboration, experiential knowledge, and situational judgement, with gaps arising when communication, documentation, or MR-specific expertise were insufficient. Conclusion: MR safety during IHT of critically ill patients is enacted through the integration of structured tools, tacit knowledge, team coordination, and spatial adaptation under conditions of uncertainty. Safety is achieved in action through collective, context-sensitive practices rather than sole reliance on protocols. Implications for practice: Radiographers play a central role in coordinating MR safety for critically ill patients. Strengthening layered safety strategies - combining checklists, time-outs, MR-specific education, and attention to spatial design - may reduce risk, support interprofessional collaboration, and enhance patient safety in MR practice.