Objective: The purpose of this study was to describe the nature and intensity of anxiety felt by patients awaiting coronary artery bypass surgery. Design: A prospective, cross-sectional study design was used, with a qualitative interview and State Trait Anxiety Inventory. Setting: Study took place in 2 large tertiary referral hospitals in Northern Ireland. Participants: Seventy patients were randomly selected within 4 weeks of their referral for cardiac surgery. Results: Participants in this study cited 5 main sources of anxiety: chest pain, uncertainty, fear of the operation, physical incapacity, and dissatisfaction with the care offered to them. The State Trait Anxiety Inventory scores of this sample were high at all stages of data collection. There was a statistically significant relationship (P≤.01) between increasing angina and state and trait anxiety. Conclusion: This study identifies the major sources of anxiety described by this sample. In doing so it may facilitate greater understanding of the needs of these patients and assist in the development of specific interventions to help alleviate this problem. (Heart Lung® 2003;32:23-31.)