We discuss the value of the non-invasive methods such as phonomecanocardiography, echocardiography and Doppler in the assessment of pulmonary arterial hypertension (PAH) The phonocardiographic record, the yugular phlebogram and the precordiogram, have a good correlation with the systolic pressure of the pulmonary artery. The two-dimensional echocardiogram is the technique of choice to determine the state of the pulmonary artery bandages after surgery and is also useful in cases of pulmonary thromboembolisms. The most reliable non-invasive method to determine the severity of the PAH is the Doppler study of the outflow tract of the right ventricle and pulmonary artery.