Incidentaloma, a term that embodies the detection of certain problems during the performance of unreasonable investigations, resonates in the medical field. Retroaortic coronary sign is a recently recognized echocardiographic feature of the anomalous coronary artery. It is typically associated with anomalies of the left coronary artery, especially the left circumflex artery. As far as has been monitored, few echocardiographic signs that correlate with this feature have been identified. This feature often remains underdiagnosed on transthoracic echocardiograms due to confusion with artifacts, calcifications, and other cardiac structures. A 45-year-old male patient underwent regular cardiac routine assessment. Retroaortic anomalous coronary (RAC) sign was incidentally detected by transthoracic thoracic echocardiogram; consequently, the retroaortic route of the coronary artery was suspected. Coronary computed tomography angiography was requested to confirm the seen echocardiographic signs. After a 3D reconstruction imaging, the left circumflex retroaortic course was identified with right coronary sinus origin. This case ensures the importance of transthoracic echocardiography as a noninvasive tool in diagnosing anomalous coronary arteries. These anomalies are usually diagnosed by coronary computed tomography angiography and coronary angiography, mainly in the presence of retroaortic coronary sign or “crossed aorta sign.”