Pulmonary hypertension (PH) has a poor prognosis. It may be idiopathic or develop secondary to various cardiac and respiratory disorders. The diagnosis of PH is challenging because its signs and symptoms are non-specific and there is no completely reliable non-invasive test for its detection. Most patients with suspected PH or with the non-specific symptoms of PH will undergo computed tomography (CT) as part of their diagnostic work-up and, therefore, it is important for radiologists to be aware of the CT signs that may suggest the diagnosis. This article will review the numerous CT signs of PH describing their individual strengths and weaknesses, and discuss how they may be applied in clinical practice.