Arrhythmias are a common complication in the adult population with congenital heart disease (ACHD). Arrhythmias often lead to hemodynamic instability and, on the other hand, may be a marker of hemodynamic impairment in ACHD patients, both in natural history and after cardiac surgery. Treatment requires knowledge of basic anatomy and any previous cardiac surgery; the availability of patient's health records, if possible, is therefore crucial for therapeutic choices. In the emergency setting, the first target is represented by the patient's hemodynamic stabilization; mainly in moderate or high complexity ACHD, the connection with the referral center is recommended, to which patients should be entrusted for follow-up. A regional epidemiological observatory, aiming to assess the number, type and outcomes of emergency admissions of ACHD patients could be a useful tool for analyzing the effectiveness of the collaboration network between the different structures involved and for implementing organizational pathways.