Background • Music Care is a smartphone-based application providing a musical intervention for the management of pain and anxiety in a clinical setting. Coronarography is a medical procedure frequently associated with examination anxiety. Objectives • The study intended to perform an initial evaluation of the application for use with patients undergoing a coronarography. Design • The research team performed an uncontrolled, observational study. Setting • The study took place at Nouméa General Hospital in Nouméa, New Caledonia, France. Participants • Participants were 35 patients, 17 women and 18 men, who were undergoing a coronarography between November 2010 and April 2011 at the Nouméa General Hospital. Intervention • Participants listened to a standardized musical sequence of adjustable length by choosing a preferred style of music (eg, classic rock or folk music) from a variety of choices that the research team had chosen to include in the application. Outcome Measures • Before and after listening to the music, all participants were asked to rate their anxiety and pain on an 11-item, visual analogue scale and to complete a questionnaire on their satisfaction with use of the application. Results • The paired sample t test revealed a significant reduction in participants' anxiety (t33 = 4.12, P < .0001) after they had listened to the music. No significant reduction in self-reported pain occurred; however, only a few participants reported pain associated with the procedure. No significant sex differences existed. Women and men both showed reduced anxiety after listening to music as well as reported a high level of satisfaction in using the Music Care application. Conclusions • The smartphone-based Music Care application is an easy-to-use tool to reduce anxiety in patients undergoing coronarography. Future large-scale, controlled trials are necessary to compare its effectiveness with other interventions. Both women and men can benefit from the use of the application.