Abstract :Left Atrial Appendage (LAA) contributes toward LA reservoir and contractile functions. However, the LAA is also the most common site for thrombus formation in Atrial Fibrillation (AF). The shape of the LAA is variable, but the absence is extremely rare. A man with no past cardiac history was admitted for catheter ablation of AF. Before the procedure, the patient underwent a Transoesophageal Echocardiography (TEE) examination, but neither cardiac thrombus nor LAA could be detected. Absence of LAA was confirmed by cardiac Computer Tomography (CT).