Introduction and objectives Atrial fibrillation (AF) is a prevalent condition that leads to a high number of consultations in clinical practice. The aim of our study is to describe the clinical characteristics of patients with AF treated in the cardiology clinic, to evaluate how cardiologists treat these patients and whether prevention of stroke performed in routine clinical practice is according to the antithrombotics criteria recommended by the 2010 European clinical practice guidelines (ECPG) in AF. Methods We analysed all patients evaluated in the cardiology clinic for two consecutive weeks during September 2010. We collected the clinical characteristics of patients, the type of AF, drug treatment, and determined the risk of stroke according to different criteria used by the ECPG. Results Of the 759 patients treated, 160 (21%) had AF, and were included in the registry. Thirty-two patients (20%) were <65 years and 137 suffered non-valvular AF. Sex differences were observed in prevalence of dyslipidaemia (49.4% vs 31.6%, P = .02), smoking (14.8% vs 3.1%, P = .01), valve disease (6.2% vs 22.8%, P = .003), age ( P = .05), peripheral arterial disease (37% vs 8.9%, P = .0001), in the rhythm in the ECG ( P = .01) and the type of AF ( P = .05) and age of these ( P = .002), but there were no differences in the treatment used. Ninety five patients were anticoagulated, but only 64% of patients with CHADS 2 ≥2, and 50% with CHA 2DS 2VASc ≥2. Conclusions One out of every 5 patients with AF evaluated in our clinics are under 65 years. The indication for anticoagulant treatment will probably increase in the next few years. The adherence to the recommendations for anticoagulation of the ECPG is good, but could be improved.