Introduction <p>Critical care (CC) nurses have a central role in stabilizing critically ill patients during high-acuity events, including disasters. However, limited evidence is available on their level of disaster preparedness (DP) and on the specific disaster competencies (DCs) required to respond effectively in such situations. Therefore, this scoping review aimed to synthesize current evidence on DP among CC nurses and to identify the DCs needed to support effective disaster response within critical care setting.</p> Method <p>This scoping review followed the Person-Concept-Context methodological framework of the Joanna Briggs Institute. A systematic search was conducted in July 2025 across MEDLINE All, Embase, Web of Science Core Collection, CINAHL Plus, and PsycINFO databases. The protocol was registered on OSF (DOI: 10.17605/OSF.IO/CAG2V). Descriptive statistics summarized study characteristics and levels of DP, while DCs were identified through thematic analysis.</p> Results and findings <p>A total of 1,834 records were retrieved, of which 62 studies ultimately were included in the final review. Results indicated that CC nurses are insufficiently prepared for disaster situations. Additionally, four key DC themes emerged: (1) Clinical critical care competencies, (2) Operational readiness and coordination, (3) Public responsibility in disaster preparedness, and (4) Intrinsic capacities for disaster response.</p> Conclusion <p>This scoping review demonstrated that CC nurses often feel unprepared to respond effectively to disasters. Four key disaster competency domains were identified that reflect the unique and multifaceted nature of disaster nursing in CC settings. These findings offer a foundation for developing context-specific education, policy, and practice to strengthen disaster preparedness among CC nurses.</p> Clinical trial number <p>Not applicable.</p>