Background <p>Mass gatherings such as the Hajj pose significant challenges to healthcare systems due to extreme crowd density, environmental stressors, and increased risk of medical emergencies. These events require robust preparedness and highly coordinated medical responses. However, existing literature indicates critical gaps in the readiness of registered nurses.</p> Aim <p>This study explores the preparedness and experiences of Registered Nurses during the Hajj, with a focus on identifying key barriers, needs, and strategies for effective disaster preparedness and response.</p> Methods <p>A qualitative exploratory design was used, involving semi-structured interviews with ten registered Nurses in Taif and Makkah cities. Data were analysed using Reflexive Thematic Analysis to explore experiences and challenges in preparedness during the Hajj.</p> Findings <p>The study identified five key themes from interviews with registered nurses involved in the Hajj mass gatherings, reflecting critical aspects of their experiences in delivering care during this mass gathering event. These themes include Hajj preparedness, disaster and crisis management, patient care management, staff well-being, and communication and coordination.</p> Conclusion <p>This study highlights the multifaceted challenges faced by registered nurses during the Hajj, emphasising the need for improved preparedness, culturally competent care, and coordinated response systems. It also reveals the importance of supporting both the technical and emotional dimensions of care to enhance healthcare delivery in mass gatherings.</p> Clinical trial number <p>Not applicable.</p>