Aim: To describe how Swedish emergency nurses experience the preconditions of providing safe care during the COVID-19 pandemic when collecting blood culture in the emergency department. Design: A qualitative exploratory design using content analysis with a manifest approach. Method: Semi-structured interviews were conducted with 13 emergency nurses working in the emergency department. Results: The analysis resulted in one main category: unprecedented preconditions create extraordinary stress and jeopardize safe care when collecting blood culture. This main category includes four additional categories: organizational changes, challenges in the isolation room, heavy workload creates great stress, and continuous learning. Conclusion: The COVID-19 outbreak has made the emergency department a workplace where constant changes of routines combined with new information and reorganization risk jeopardize safe care during blood culture sampling. Accordingly, high workload and stress have been identified as a reason for emergency nurses not following guidelines. It is therefore necessary to optimize the preconditions during blood culture sampling and identify situations where there are shortcomings.