Anxiety is common in critically ill patients and can adversely affect recovery if not properly assessed and treated. The objectives of this study were to: (1) identify the clinical indicators that critical care nurses consider to be the defining attributes of anxiety in critically ill patients; and (2) delineate the interventions that critical care nurses use to alleviate anxiety in their patients. A total of 2500 nurses who worked in adult critical care areas were randomly selected from the membership of the American Association of Critical Care Nurses. Nurses selected were mailed a survey designed to determine what they considered to be the important attributes of anxiety in their patients and what interventions they commonly used to manage anxiety. The 593 nurses (31.6% response rate) who responded identified 70 individual anxiety indicators and 61 anxiety management strategies that were categorized into four and three major categories, respectively. The four major anxiety assessment categories were: (1) physical/physiological; (2) behavioral; (3) psychological/cognitive; and (4) social. The three major anxiety management strategies were: (1) care techniques; (2) improving knowledge and communication; and (3) support. Critical care nurses reported numerous and distinctive anxiety indicators and management strategies. Further research is needed to examine exactly how appropriate and effective these assessment indicators and management strategies are.