It is essential to diagnose pulmonary arterial hypertension in early stages of the disease. However, most patients have late diagnosis due to the lack of disease-specific symptoms and prominent findings. Although cardiac catheterization is the gold standard in the diagnosis of pulmonary arterial hypertension, noninvasive diagnostic modalities do also have major roles in the diagnosis, risk assessment and follow-up of the patients with pulmonary arterial hypertension. The focus of the present review is the clinical role of echocardiography and other imaging modalities in pulmonary arterial hypertension.