Aim To describe newly graduated nurses' experiences of taking responsibility to ensure safe nursing care in their first year and how COVID-19 affected their professional development.Background Newly graduated nurses faced many challenges and great pressure from healthcare to take responsibility to ensure safe nursing care under their first year in the profession. Challenges increased with COVID-19, possibly affecting safe nursing care and the psychosocial work environment.Design A descriptive qualitative design was chosen and data were collected through group interviews from nurses in their first year as newly graduated nurses (n = 15) in the middle of Sweden. Semi-structured interviews were conducted digitally, and inductive thematic analysis was used to analyse the data.Results The experiences of newly graduated nurses were summarized along two themes: Own responsibility from start and Challenges lead to professional development. The participants described how they initially had to take full responsibility for patient's care. They described feelings of inadequacy and uncertainty in relation to safe nursing care and highlighted a lack of support from more experienced colleagues. They had to take their own initiative more, conduct complex caregiving, and had the opportunity to share experiences with other professions. The pandemic contributed to increased demands on their own responsibility for patient's care. Experiences were both positive and negative, and different challenges led to professional development.Conclusion Newly graduated nurses felt that challenges and responsibility led to their development in the profession. Support and competence development are needed in their first year.Implications for the Profession and/or Patient Care Newly graduated nurses should be offered continuous support and well-organized competence development to enhance professional self-confidence. Well-functioning teams create a sense of belonging, where knowledge and experience are exchanged, leading to professional development.Patient or Public Contribution There was no patient or public contribution.