Background <p>Catheter-associated urinary tract infection (CAUTI) is a frequent and preventable healthcare-associated infection. Nurses play a central role in CAUTI prevention, yet barriers to consistent implementation of evidence-based practices persist. In Portugal, few studies have explored nurses’ lived experiences in this area. This study aimed to explore Portuguese oncology nurses’ perceptions of barriers and facilitators to CAUTI prevention, and to identify suggestions for improving urinary catheter-related care.</p> Methods <p>An exploratory qualitative study was conducted with a purposive sample of eight oncology nurses from a Portuguese oncology hospital. Data were collected through a 90-minute focus group, in February 2023, and analyzed using inductive thematic analysis. The Nursing Role Effectiveness Model informed data interpretation and theme organization.</p> Results <p>Two main domains emerged: structural variables and process-related variables. Nurses identified facilitators such as continuing education, access to catheterization kits, and a positive team culture. Barriers included inconsistent material availability, gaps in supervision of delegated tasks, variability in catheterization practices, and challenges in interprofessional communication. Patient and family engagement was rarely mentioned, suggesting that CAUTI prevention was conceptualized primarily as a nurse-driven activity. Nurses valued opportunities for reflective practice and expressed interest in standardized protocols and improved documentation systems.</p> Conclusions <p>Oncology nurses demonstrated strong engagement in CAUTI prevention, yet gaps remain in supervisory practices and patient involvement. Fostering reflective practice, enhancing supervisory skills, and broadening conceptions of nurse-sensitive outcomes may support more comprehensive and sustainable CAUTI prevention strategies in clinical practice.</p> Clinical trial number <p>Not applicable.</p>