Background and Aims Evidence‐based practice (EBP) is central to high‐quality acute care, yet evidence on how specialist nurses engage with EBP remains limited. This study aimed to examine EBP beliefs, organisational culture, and self‐reported implementation among specialist nurses working in acute care, and to assess associations with professional characteristics, including specialist certification and academic qualifications. Design A descriptive cross‐sectional study. Methods Data were collected between June and November 2023. Participants were specialist nurses employed in acute care roles, including critical care, emergency and urgent care, specialist medical and surgical units, and advanced practice positions. Validated instruments were used to measure EBP beliefs, organisational culture, and implementation. Analyses included descriptive statistics, group comparisons, and multivariable regression models. Results A total of 510 specialist nurses were included. Overall, nurses reported strong beliefs in EBP, moderately positive perceptions of organisational culture, and variable levels of implementation. Specialist certification was consistently associated with higher EBP implementation (standardised β = 0.24, 95% CI 0.15–0.33) and more positive organisational culture perceptions ( β = 0.19, 95% CI 0.07–0.31), independent of experience and academic qualification. A clear pattern across clinical areas was observed, with higher EBP engagement reported in adult critical care and advanced practice roles, and lower organisational culture scores in emergency care settings. Conclusion Among specialist nurses working in acute care, positive beliefs about EBP are widespread, but implementation varies and is associated with specialist certification and organisational context rather than years of experience or academic attainment. These findings highlight the importance of certification pathways and supportive organisational environments in strengthening EBP in high‐acuity settings.