Atrial fibrillation (AF) is the most common chronic cardiac arrhythmia and is an important risk factor for mortality and morbidity related mainly to an increased risk of cerebrovascular events and heart failure.An observational cross-sectional study was performed to evaluate the use of healthcare resources (including hospital and outpatient care) by patients with AF in the Lazio region (central Italy), from 1 January 2006 to 31 December 2008.Atrial fibrillation is an important source of healthcare resource utilization because of repeated emergency room visits, hospital admissions, outpatient consultations and procedures and extensive use of laboratory tests and pharmacological treatments.Results show that 55% of costs are attributable to hospital admissions and Emergency Room visits, 37% to pharmacological treatment and the remaining 8% to outpatient care. These results are consistent with the international literature.The impact of AF in terms of cost is not negligible and it is therefore desirable to implement an organizational scheme that safeguards the appropriateness of care, taking charge of the patient as early as possible. The aims of early diagnosis of AF are to improve the appropriateness of care and optimize the use of specialized tests, thereby reducing hospital admissions for complications or recurrences of AF.