BACKGROUND The influence of atrial fibrillation (AF) on outcome in patients with symptomatic atherosclerotic disease has not been thoroughly studied. METHODS FRENA is an ongoing registry of stable outpatients with coronary (CAD), cerebrovascular (CVD), or peripheral (PAD) artery disease. With the aim to guide therapy, we assessed the incidence of subsequent myocardial infarction (MI), ischemic stroke or major bleeding in patients with AF, according to initial presentation. RESULTS As of June 2011, 3848 patients were recruited: 1436 had CAD, 1104 CVD, and 1308 had PAD. Of these, 470 (12%) had AF: 151 patients with CAD, 157 with CVD, and 162 with PAD. Over a mean follow-up of 16 ± 13 months, 19 patients with AF developed acute MI, 22 ischemic stroke and 7 bled. Among AF patients with CAD, the incidence of subsequent MI (5.00 events per 100 patient-years; 95% CI: 2.54-8.91) was non-significantly higher than that of stroke (1.48; 95% CI: 0.38-4.04) or major bleeding (1.47; 95% CI: 0.37-4.01). Among those with CVD, the incidence of stroke (5.61; 95% CI: 2.95-9.75) exceeded that of MI (no events) or major bleeding (0.51; 95% CI: 1.24-6.36). Among those with PAD, the incidence of MI (4.41; 95% CI: 2.15-8.10) and stroke (3.93; 95% CI: 1.82-7.46) were similar. CONCLUSIONS CAD patients with AF are at a higher risk of subsequent MI than of stroke. Among those with CVD, the risk of stroke far exceeds that of MI. Those with PAD have a high and similar risk for both events.