Despite being one of the most prevalent cardiac arrhythmias, the cause of atrial fibrillation (AF) in a vast majority of patients remains unknown. There is growing evidence of associated AF in patients diagnosed with coronary arteriovenous fistula. In this discussion, we have included an example of a patient who presented with new-onset AF and was subsequently diagnosed with an anomalous fistula between the right coronary artery and the superior vena cava. Definitive treatment of the fistula resulted in permanent resolution of the AF. Based on this case and a similar case reported in the literature, it is proposed that further research will unmask this possibly underdiagnosed and very treatable cause of AF.