In order to determine the tightness of the pulmonary artery band, Doppler echocardiography is used to assess mitral valve flow velocity, which is an indirect indicator of pulmonary blood flow. The band is tightened until the velocity decreases to 70% of the original maximal level. Additional adjustment of the constriction is then made to obtain reasonable arterial oxygen saturation, heart rate and ventricular contractility. Using this method, 12 consecutive patients underwent pulmonary artery banding with satisfactory results. This technique is simple but useful in obtaining optimum constriction of the pulmonary artery in congenital heart disease with excessive pulmonary blood flow.