Purpose: This study was conducted to investigate the correlation among nurses" knowledge, performance, and stress about care for delirium. Methods: The data were collected using the instruments for knowledge about nursing care (50 items), performance (23 items), and stress (20 items). Descriptive statistics and Pearson’s correlation coefficient were used to analyze the data of 222 participants. Results: Nursing knowledge were different by clinical experience (F=3.12, p=.016), position at work (t=-2.54, p=.012), experience in caring patients with delirium (t=3.90, p<.001), and conflicts with other disciplines on matters related to delirium (t=4.00, p=.001). The difference in performance were associated with age (F=4.19, p=.001), clinical experience (F=2.67, p=.003), and whether there was a guideline for managing the patients with delirium (t=2.30, p=.022). Stress of nurses was different by whether they had a religion or not (t=-2.41, p=.017). The knowledge of care for delirium had the positive relationship with performance (r=.21, p=.001) and negative relationship with stress (r=-.29, p=.001). Conclusion: It is necessary to develop educational program and guideline for improving the knowledge and performance in care for delirium among nurses working at orthopedic hospitals.