This article reports two cases of atrio-esophageal fistulas (AEF) that occurred in patients undergoing percutaneous transesophageal pulmonary vein ablation for atrial fibrillation (AF). Both patients developed symptoms compatible with endocarditis 3 to 5 days post-procedure, including fever, chest pain, and convulsions. They experienced rapid deterioration and suffered multiple gaseous and septic embolic events, leading to cerebral and myocardial damage. One patient survived after emergency cardiac and esophageal surgery, while the other died due to extensive systemic embolization. An AEF was identified in both patients. The authors emphasize the importance of excluding AEF in patients presenting with symptoms of endocarditis after AF ablation and highlight the critical need for prompt surgical intervention if the diagnosis is confirmed. They suggest that lower power and temperature settings during radiofrequency energy applications along the posterior left atrial wall may help prevent AEF formation.This article reports two cases of atrio-esophageal fistulas (AEF) that occurred in patients undergoing percutaneous transesophageal pulmonary vein ablation for atrial fibrillation (AF). Both patients developed symptoms compatible with endocarditis 3 to 5 days post-procedure, including fever, chest pain, and convulsions. They experienced rapid deterioration and suffered multiple gaseous and septic embolic events, leading to cerebral and myocardial damage. One patient survived after emergency cardiac and esophageal surgery, while the other died due to extensive systemic embolization. An AEF was identified in both patients. The authors emphasize the importance of excluding AEF in patients presenting with symptoms of endocarditis after AF ablation and highlight the critical need for prompt surgical intervention if the diagnosis is confirmed. They suggest that lower power and temperature settings during radiofrequency energy applications along the posterior left atrial wall may help prevent AEF formation.