Post-pericardiotomy syndrome may occur after traumatic insults to the pericardium but has not been reported after radiofrequency catheter (RF) ablation. A 54 year old man underwent extensive linear left atrial RF ablation for chronic atrial fibrillation. Five days after the procedure the patient developed signs and symptoms of the post-pericardiotomy syndrome and showed new, intense pericardial inflammation on magnetic resonance imaging. After intensive medical management, the patient recovered fully. It is believed that the patient experienced a unique complication of linear left atrial ablation, i.e., post-pericardiotomy syndrome due to extensive left atrial necrosis or direct thermal pericardial injury.