Implantable defibrillator systems have been used in over 20000 patients worldwide. Such systems use a variety of different electrodes and the identification of these and the recognition of associated problems with them presents a challenge to the radiologist. The appearance of currently available implantable defibrillation systems and the use of radiological examination in patient follow-up and system troubleshooting is discussed based on our experience with a large population of patients receiving these devices. Radiological examination is excellent for demonstrating displacement or distortion of defibrillation electrodes, but in our experience is ineffective for the identification of lead conductor fractures.