BACKGROUND & AIMS: Pulmonary arterial hypertension is a severe disease associated with frequent hospitalisations. This retrospective analysis of the French medical information PMSI-MSO database aimed to describe incident cases of patients with pulmonary arterial hypertension hospitalised in France in 2013 and to document associated hospitalisation costs from the national health insurance perspective. METHODS: Cases of pulmonary arterial hypertension were identified using a diagnostic algorithm. All cases hospitalised in 2013 with no hospitalisation the previous two years were retained. All hospital stays during the year following the index hospitalisation were extracted, and classified as incident stays, monitoring stays or stays due to disease worsening. Costs were attributed from French national tariffs. RESULTS: 384 patients in France were hospitalised with incident pulmonary arterial hypertension in 2013. Over the following twelve months, patients made 1,271 stays related to pulmonary arterial hypertension (415 incident stays, 604 monitoring stays and 252 worsening stays). Mean age was 59.6 years and 241 (62.8%) patients were women. Liver disease and connective tissue diseases were documented in 62 patients (16.1%) each. Thirty-one patients (8.1%) died during hospitalisation and four (1.0%) received a lung/heart-lung transplantation. The total annual cost of these hospitalisations was € 3,640,382. € 2,985,936 was attributable to standard tariffs (82.0%), € 463,325 to additional ICU stays (12.7%) and € 191,118 to expensive drugs (5.2%). The mean cost/stay was € 2,864, ranging from € 1,282 for monitoring stays to € 7,285 for worsening stays. CONCLUSIONS: Although pulmonary arterial hypertension is rare, it carries a high economic burden.