We report a case in which pulsed wave Doppler echocardiography and color flow imaging of blood flow direction in an anomalous coronary artery from the pulmonary artery assisted in the correct diagnosis and confirmed the adequacy of the surgical correction. Low-velocity color scales were used to show retrograde filling of the left coronary artery before surgery and antegrade filling of the left coronary artery after surgery. Detecting direction of blood flow in coronary arteries should increase the accuracy of the noninvasive diagnosis of anomalous left coronary artery from the pulmonary artery.