BACKGROUND Atrial fibrillation is a common arrhythmia worldwide. The number of patients undergoing ablation as treatment is increasing, as is the incidence of complications from ablation. One such complication is atrio-esophageal fistula, which is rare but life threatening. We discuss 2 cases of patients that presented with a fistula several weeks following atrial fibrillation ablation. CASE REPORT A 67-year-old man and 64-year-old woman both had cardiovascular morbidity and chronic kidney disease, diabetes, and other chronic illnesses. Both patients presented approximately 6 weeks after radiofrequency atrial fibrillation ablation and were admitted with varying symptoms, including fever and neurological deficits mimicking a cerebrovascular accident or massive bleeding. Both patients deteriorated very rapidly in the department, especially after certain interventions, such as endoscopy, and exhibited deteriorating neurological signs, including loss of consciousness and basic brain stem reflexes, and head computed tomography (CT) showed widespread infarcts and hemorrhages. Owing to their history, a chest CT was performed at the same time, revealing an atrio-esophageal fistula, which was determined to be the cause of their illness and led to their eventual deaths. CONCLUSIONS A rare complication of atrial fibrillation ablation procedure is atrio-esophageal fistula, which if left untreated, is almost uniformly fatal, and even survivors are usually left with significant sequelae. It is important to recognize the rapid deterioration and possible signs and symptoms, such as gastrointestinal bleeding, fever, or even neurological abnormalities, and make the connection to the ablation procedure in terms of timeline for rapid diagnosis and prompt treatment.