Objective Intra-hospital transport (IHT) of critically ill patients is associated with morbidity and mortality. Mass transfer of patients, as happens with unit relocation, is poorly described. We outline the process and adverse events associated with the relocation of a critical care unit. Design Extensive planning of the relocation targeted patient and equipment transfer, reduction in clinical pressure prior to the event and patient care during the relocation phase. Setting The setting was a 30-bed, tertiary referral, combined medical and surgical critical care unit, located in a 570-bed hospital that serves as the national referral centre for cardiothoracic surgery and spinal injuries. Participants All stakeholders relevant to the critical care unit relocation were involved, including nursing and medical staff, porters, information technology services, laboratory staff, project development managers, pharmacy staff and building contractors. Main outcome measures Mortality at discharge from critical care unit and discharge from hospital were the main outcome measures. A wide range of adverse events were prospectively recorded, as were transfer times. Results Twenty-one patients underwent IHT, with a median transfer time of 10 min. Two transfers were complicated by equipment failure and three patients experienced an episode of hypotension requiring intervention. There were no cases of central venous or arterial catheter or endotracheal tube dislodgement, and hospital mortality at 30 days was 14%. Conclusion Although IHT is associated with morbidity and mortality, careful logistical planning allows for efficient transfer with low complication rates.