Assessment of pulmonary arterial pressure can be made by clinical examination, especially ausculation, X-Ray and electrocardiography. The maintenance of normal pulmonary arterial blood pressure depends on the relationship between pulmonary blood flow and pulmonary vascular resistance. Three principal ways in which pulmca hypertension occurs have been given namely, direct transmission of pulmonary venous hypertension, kinetic pulmonary hypertension and increased vascular resistance in the pulmonary circuit. Surgical t.a is effective and curative of these complications. Vasoconstrictive pulmonary hypertension in mitral ve obstruction could be cured by mitral valvotomaerative treatment in Eisenmenger syndrome is ind if pulmonary artery pressure falls to normal level exhibition of tolazoline in the main pulmonary.