Background The number of disasters occurring globally is increasing. Natural hazards, changing geopolitical situations, and increasing population densities may lead to an increased likelihood of a surge of patients requiring health care, some of whom might be requiring intensive care–level treatment. There is a dearth of literature on intensive care unit (ICU) practitioner's priorities regarding disaster preparedness and crisis standards of care. Objectives This study aimed to understand what nurses working in ICUs within Australia prioritise regarding ICU disaster preparedness and the implementation of crisis standards of care. Methods A modified three-round Delphi design was used for this study. A snowballing recruitment method facilitated the purposive sampling of ICU nurses, starting with members of the Australian College of Critical Care Nurses. Eligible participants were asked to rate statements according to their priorities when addressing disaster preparedness of the Australian ICU in which they work. Statements that achieved the 10 highest scores in the final round were tabulated to indicate the broader areas of disaster preparedness that the respondents considered priorities. Results A total of 16 participants completed both round two and round three of this Delphi study. Out of 38 statements across six domains, 33 statements achieved consensus. Healthcare practitioner protection, wellbeing, and the management of space populated the top 10 priorities. These priorities included adequate personal protection equipment, services to support healthcare practitioners, and clear communication and debriefing pathways. Another key priority identified was the need for a clear plan on how the ICU footprint will expand to accommodate a surge of patients. Conclusion Healthcare practitioner wellbeing followed by adequate plans for ICU expansion are key priorities of nursing staff working in ICUs within Australia. Understanding the priorities of those who work in the ICU gives a pragmatic insight into what is required to further develop the disaster preparedness of Australian ICUs.