Aims: Identify the organizational changes faced by front- line nurses working with COVID- 19 patients during the first wave and describe how they responded to these changes. Background: The COVID-19 pandemic has altered the provision of care and the management of health care around the world. Evolving information about SARS-coV-2 meant that health care facilities had to be reorganized continually, causing stress and anxiety for nurses. Methods: Qualitative study based on Rapid Research Evaluation and Appraisal (RREAL). The research took place in Hospital and community health settings of the Spanish national health system with a purposive sampling of 23 front- line nurses. Semi-structured interviews were conducted between May and June 2020. The duration was 30 to 45 minutes per interview. We used the Dedoose® data analysis software to perform a thematic analysis. Results: Nurses responded to organizational changes using the following strategies: improvisation, adaptation, and learning. Conclusion: Our rapid approach allowed us to record how nurses responded to changing organization, information that is easily lost in a disaster such as the COVID-19. Implications for Nursing Management: Knowing about their strategies can help planning for future health disasters, including subsequent waves of the COVID-19.