Purpose: The aim of this study was to assess nurses’ evidence-based practice (EBP) beliefs and competencies, and organizational supports to develop EBP. Methods: A descriptive study was conducted using a survey of clinical nurses at a tertiary hospital in South Korea. Results: The survey was distributed to a total of 1,413 nurses and was completed by 1,318 nurses. There were significant differences in the EBP beliefs and competencies, and the perception of organizational supports among nurses at different educational levels. The EBP beliefs, EBP competencies, and organizational supports had a positive correlation with each other. EBP competencies were the highest in nurses with less than 3-years of clinical experience, and the perception of organization supports were the highest in nurses with more than 10-years of clinical experience. Conclusion: The findings suggest that educational programs, training, and organizational supports are recommended for facilitating successful EBP among nurses.