This case report demonstrates a role for transesophageal echocardiography in defining the course of anomalous coronary arteries. Origin of the right coronary artery (RCA) from the left main (LM) (single coronary artery) is an exceedingly rare congenital anomaly. It is not always benign and may result in myocardial infarction. This may be due to compression between the aorta and the pulmonary artery. Transesophageal echocardiography offers a low-risk, noninvasive means of imaging the proximal coronary arteries. In the majority of patients, the proximal segments of the three major coronaries can be clearly visualized. With the addition of color flow, it is possible to visualize flow in most patients. Proximal obstructive lesions can be seen in some patients although sensitivity thus far seems low.