Catheter angiography is now more commonly used for various endovascular interventions on pulmonary circulation, such as mechanical embolectomy, embolization for tumors or retrieval of foreign bodies, as well as for the diagnosis and treatment of a variety of congenital heart diseases (CHDs). The main pulmonary artery (PA) originates from the right ventricle (RV), travels anteriorly on the left side of the aorta, and then follows a posterior course, bifurcating into the right and left pulmonary arteries. Pulmonary embolism (PE) is one of the most important causes of cardiovascular morbidity and mortality with an annual incidence of 1 per 1,000 in the general adult population. Pulmonary angiography and right heart catheterization can be utilized to both confirm the diagnosis and evaluate the possibility of surgical or endovascular treatment in a patient with pulmonary hypertension secondary to chronic thromboembolic disease. Pulmonary angiography is usually performed in the acute setting for evaluation and catheter-directed treatment of massive or submassive PE.