Pulmonary arterial hypertension (PAH) remains an incurable disease associated with an unacceptably high early mortality, despite advances in therapeutic options. The disease is clinically silent until late in its natural history, when most of the distal pulmonary arteries have been obliterated. Early diagnosis of PAH is associated with improved long-term survival, and screening of at-risk populations is, therefore, a rational strategy to improve outcomes in this condition. Doppler echocardiography is the most widely used screening tool in current clinical practice. The role of evidence-based screening strategies has been clarified by research such as the DETECT study in patients with systemic sclerosis. A multimodal approach, using a range of noninvasive tests, improves the performance of screening algorithms. Right heart catheterization is mandatory to confirm a diagnosis of PAH. Uncertainties exist about the definition and prognostic relevance of pulmonary hypertension during exercise, but accumulating evidence suggests that stress testing of the pulmonary circulation can unmask clinically important early disease. Novel tools for the early detection of pulmonary vascular disease are urgently needed, given the substantial limitations of currently available techniques.