Pulmonary arterial hypertension (PAH) is a rare, incurable and often fatal disorder of the lung in which pulmonary artery pressure rises to abnormal levels. It may either be idiopathic in nature (primary pulmonary hypertension) or a manifestation of many different disorders (secondary pulmonary hypertension). Current management includes prostacyclin vasodilator therapy, and conventional therapy consisting of calcium channel blockers, anticoagulation, oxygen therapy and diueresis; and newer agents such as bosentan, an endothelin antagonist. To date, no systematic review has assessed these interventions. OBJECTIVES: To perform a systematic review of the medical interventions used in the management of PAH. METHODS: A literature search of EMBASE and MEDLINE was performed, and studies matching the predefined inclusion criteria extracted to HTA-standardised grids and graded using the Jadad score. Data for three outcome measures survival, exercise capacity and right atrial pressure were extracted as these were deemed the most clinically relevant outcome measures. Where possible, data was segregated according to intervention, the type of PAH and the functional class of patients evaluated in the studies. RESULTS: The literature search yielded 1503 abstracts. Of these, 54 were included after first pass assessment. Twenty- eight papers were included after second pass assessment, and were extracted. The mean Jadad score was 1.56 (range 0-5). Mean ages for primary and secondary pulmonary arterial hypertension were 41 and 47 respectively. Three-year survival rates were 49% to 76% across all interventions. Mean changes in right atrial pressure ranged from -6 to 2 mmHg, whilst mean changes in exercise capacity varied from -189 to 132 m. CONCLUSION: The variable quality of the reviewed articles is partly due to the ethical difficulties in trial design in this disease area. Quantitative comparisons of the interventions are difficult within the context of this review, but the homogeneity of the data may make meta-analysis of the evidence possible.