Introduction: COVID-19 is a new disease infecting a large number of people, and undoubtedly have psychological impacts on healthcare workers. Among healthcare staff, nurses are the most involved ones in fighting against COVID-19. Therefore, this study aimed to explore nurses’ experiences of psychological consequences during caring patients with COVID-19. Methods: The present qualitative study was conducted using the conventional content analysis approach (Graneheim and Lundman) Iran. Participants in this study included 15 nurses working with patients with COVID-19, selected by purposive sampling. Data were collected using in-depth interviews. The rigor of data was assessed using the criteria proposed by Guba and Lincoln. Results: Nurses reported the four following psychological consequences of COVID-19 pandemic on caring patients with COVID-19: post-traumatic stress disorder, depression, physical exhaustion, and aggressive behaviors. Conclusion: The data showed that nurses experienced a variety of psychological consequences during caring patients with COVID-19. Therefore, it is necessary to monitor nurses’ psychological problems and implement interventions to improve their mental health.