Multidetector computed tomography angiography is increasingly used to visualize the coronary tree. It is emerging as the test of choice for the detection of anomalous coronary artery origin. It provides excellent spatial resolution and the ability to see the course of the coronary arteries and their proximity to adjacent structures. Invasive angiography has been the gold standard but does not allow the visualization of adjacent anatomic structures, which is crucial to correctly diagnosing the anomaly and determining the prognosis. We report a case of a 47-year-old woman with an anomalous left main coronary artery that arises from the right sinus of Valsalva where multidetector computed tomography angiography was key to the diagnosis and provided additional information that was not discernible from the invasive angiography.