Pulmonary Hypertension (PH) is a haemodynamical disorder; its definite diagnosis requires an increase of mean pulmonary arterial pressure measured by right heart catheterization (RHC). This invasive test allows to distinguish between precapillary and postcapillary PH and also to measure the vasoreactivity before starting specific therapy. Pulmonary arterial hypertension (PAH) – group 1 of PH – comprises heterogeneous condition which presents identical histological findings. In the recent guidelines, task force suggests that transthoracic echocardiography (TTE) should be considered as a tool for assessment of the likely presence or absence of PH with different level of evidence. On the basis of this assessment patients can be referred for a confirmatory RHC. In addition to its role in diagnosis, TTE can be used to screen for high-risk patients population, to asses prognosis and to monitor disease stability and response to treatment. Even if TTE doesn't prove yet its major role in management of PAH patients, it is essential to include this safe and noninvasive exam in a goal-oriented approach to therapy.