OBJECTIVES: Atrial fibrillation (AF) is associated with numerous cardiovascular (CV) complications. The objective of this study was to estimate the national annual burden of CV complications in patients with AF in hospitals. METHODS: All patients hospitalized in 2012 with a diagnosis of AF were identified from the French National public/private hospital database (PMSI). Comorbidities and medical data were collected during a 5-year look-back period and used to calculate stroke risk score (CHA2DS2-VASc). Reasons for CV-related hospitalization, emergency admission, rehabilitation and death at discharge were described. Costs of acute care were determined using Diagnosis Related Groups and corresponding tariffs (2012 Euros). RESULTS: In total, 533,044 AF patients were hospitalized for any reason. Mean age was 78.0(±11.4) years, 53% were males and mean CHA2DS2-VASc score was 4.0(±1.8). CV-related hospitalizations occurred in 267,681 patients: 34% for AF management care, 28% for heart failure, 8% for strokes, 7% for other ischemic heart diseases, 5% for vascular diseases, 4% for transient ischemic attacks and systemic embolisms, 2% for bleedings and 12% for other CV reasons. In CV-related hospitalizations, 45% of patients required emergency admission, especially patients hospitalized for strokes (75%) and for bleedings (67%). Death at hospital occurred in 6% of patients with a CV-related hospitalization: 17% in patients with strokes and 10% in patients with bleedings. Rehabilitation was needed for 34% patients with non-fatal strokes with a mean length of 48 days. The annual total cost (acute care and rehabilitation) for all hospitalized CV events during the year 2012 was €1.94 billion. Among this, heart failure represented €518m, AF management €306m, strokes €291m and hemorrhages €48m. CONCLUSIONS: A half-million AF patients were hospitalized in 2012 in France. CV-related hospitalizations involved over a quarter-million AF patients for a global burden of almost €2 billion.