Purpose: : This study aims to investigate the status of delirium intervention in adult intensive care unit (ICU) patients and the perception of this delirium by medical staff. Methods: : This retrospective study involves 185 patients, whereas, a descriptive survey is conducted with 197 medical staff members. Results: : The delirium group includes 100 patients (54.1%). The incidence of delirium is 64.9% in the medical ICU, 65.9% in the surgical ICU, 42.4% in the neuro ICU, and 46.5% in the cardiac ICU. The percentages of delirium prevention intervention differs between the two groups: 65.0% in the delirium group and 95.3% in the non-delirium group. The medical staff recognize that delirium is a common problem in the ICU (100.0%) and requires active medical intervention (98.5%). Conclusion : The length of stay at the ICU is longer in the delirium group than in the non-delirium group. It is necessary to standardize delirium prevention and treatment protocols to be equally applicable to all ICU patients.