pulmonary hypertension occurs when the pressure of the pulmonary artery is disproportionally high for a certain level of pulmonary blood flow. values of mean pulmonary artery pressure of more than 25 mm hg at rest or 30 mm hg during exercise allow the diagnosis of pulmonary hypertension. sustained or chronic pulmonary hypertension may be secondary to known diseases, mainly to those of cardiac or pulmonary nature, or may be a primary abnormality of the pulmonary circulation, with or without identification of associated conditions. advances in the knowledge of the mechanisms of vasoconstriction and vascular remodeling have brought better prospects for the treatment of the disease. the correct use of vasodilators and anticoagulants, the new vasodilators, as epoprostenol and its analogs, and surgical techniques have increased the survival of many patients. pneumologists can view cases of pulmonary hypertension as complications of pulmonary diseases or as a result of dyspnea investigation. despite its etiology, pulmonary hypertension represents a clear abnormality that affects the right ventricle and can be potentially fatal to patients. image methods have made the diagnosis of pulmonary hypertension more accessible and non-invasive. six cases of patients with pulmonary hypertension of different causes are presented and discussed. in conclusion, according to new concepts, idiopathic pulmonary hypertension is no longer an irreversible condition, and the identification of associated conditions with potential treatments can be favorable in the management of the patients with pulmonary hypertension.