Control of stress and anxiety and the promotion of comfort are challenges facing health practitioners involved in catheterization. The aim of this case–control study was to examine the effect of music on the levels of anxiety, stress, and depression experienced by patients undergoing coronary angiography, as measured by the 21-item Depression Anxiety Stress Scales. Differences in pre- and post-intervention scores demonstrated that there were significant decreases in mean scores of state anxiety (P = 0.006), stress (P = 0.001) and depression P = 0.02) in the intervention group, who listened to 20 minutes of relaxing music, as compared with the control group who had 20 minutes of bed rest.