Pre-procedure CT and MRI angiography are commonly used for delineation of the complex and variable relationship of the left atrium, pulmonary veins, and surrounding anatomy.  Such 3D angiography is now routinely incorporated into electroanatomic mapping systems to guide ablation lesion placement in the context of patient specific anatomy.  Post-procedure CT and MRI have also proven useful for evaluating complications such as PV stenosis.   In the future, MRI and CT may be used to visualize more detailed tissue characteristics such as atrial fibrosis and ablation lesions, which could improve selection of patients for different treatment strategies and perhaps direct more effective ablation.  This review will discuss current and emerging applications of CT and MRI before and after RF catheter ablation of atrial fibrillation.