OBJECTIVES: The aim of this study was to review the existing treatment patterns for patients diagnosed with pulmonary arterial hypertension in the UK, France and Germany. METHODS IMS Disease Analyzer, a longitudinal patient database providing information from continuing physician-patient interaction on consultations, diagnoses and treatment within Primary Care, was used to review the treatment patterns for PAH patients in the UK, France and Germany over a two year period, in order to describe: 1) different therapies used; 2) combination therapies; 3) clinical and economic outcomes of different therapies; 4) dose and drug utilization patterns; and 5) resource utilization. RESULTS In all three countries, the prevalence of PAH was found to increase with age, with two-thirds of PAH patients being 60 years of age or older, with more female than male patients being diagnosed with PAH. PAH patients were also found to have been prescribed at least one medication, with 23% in France, 15% in Germany and 56% of patients in the UK being prescribed between 3 and 6 medications. In the UK, most prescriptions were found to refer to diuretics, calcium channel blockers and anti-thrombotic agents. In France, most prescriptions referred to beta-blockers, angiotensin receptor blockers and diuretics. In Germany, most prescriptions referred to diuretics, calcium channel blockers and beta blockers. For PAH patients in both France and Germany the median number of days receiving therapy over the 2 year period was found to be 100 days, whereas in the UK, this figure rose to 500 days. CONCLUSIONS Whilst there were many similarities in the sociodemographic profile of PAH patients, many differences in the treatment patterns for patients diagnosed with PAH in the UK, France, and Germany were found.