Detailed anatomic imaging of the left atrium and related structures prior to ablation of atrial fibrillation (AF) is important for planning the procedure, enabling the use of advanced mapping techniques, and avoiding complications. Multidetector computed tomography (MDCT) allows visualization of the entire left atrium and each pulmonary vein (PV). This method provides precise delineation of anatomical features and dimensions by several types of reconstructed images. Additionally, the MDCT images are used with the electroanatomical mapping system to help guide the safe and effective catheter ablation of AF. MDCT also has been used for the assessment of serial changes in ablated PVs to detect and evaluate PV stenosis. The use of MDCT greatly aids the planning and complication-free execution of AF ablation.