Nurses are imperative for healthcare systems’ ability to effectively function during pandemics, yet multiple factors may affect their willingness and preparedness to work. The aim of the present cross-sectional survey was to identify factors associated with registered nurses’ (RN) willingness and preparedness to work during the novel coronavirus disease (COVID-19) pandemic. The study was reported following the STROBE guidelines. A total of 358 nurses completed a self-administered online questionnaire. The participants were a part of a COVID-19 task force at a Danish university hospital during spring 2020. The results showed that the majority of RNs felt a professional obligation to engage in clinical work during the pandemic; however, their willingness and preparedness to work were affected by multiple factors, such as being relocated voluntarily, being prepared for the task and feeling safe. This study highlights that these factors are essential for the hospital management and nurse leaders to take responsibility for.