BACKGROUND: Delirium remains significantly undetected in the intensive care unit (ICU). Little is known regarding the level of delirium care knowledge among critical care nurses in Taiwan. PURPOSE: This study was designed to investigate the level of knowledge about delirium care among critical care nurses using a multiple-choice question quiz. METHODS: A descriptive, cross-sectional approach was used, and data were collected using a web-based survey. The demographic characteristics including age, years worked as critical care nurse, gender, advanced ICU training, educational level, and type of ICU, along with a delirium care knowledge quiz, were collected. The quiz consisted of 16 items measuring (a) symptoms, types, and outcomes; (b) high-risk groups; (c) predisposing and precipitating factors; and (d) assessment and detection of delirium. Data were collected between October 6 and November 16, 2020. RESULTS: In total, 324 critical care nurses completed the survey. The rate of correct response on the delirium care quiz for each domain was measured: (a) symptoms, types, and outcomes: 67.1%; (b) high-risk groups: 76.2%; (c) predisposing and precipitating factors: 78.9%; and (d) assessment and detection: 41.5%. The item with the lowest correct response rate was related to the interpretation of delirium assessments. CONCLUSION/IMPLICATIONS FOR PRACTICE: The findings of this study suggest that future studies and education should focus on the use and interpretation of the assessment using a valid delirium assessment tool to improve the ability of critical care nurses to detect delirium in ICU settings.