With the growing numbers of patients having implantable pacemakers and cardioverter defibrillators, the anaesthesiologest should be aware of some information regarding these devices and the anaesthetic management for such patients. Such information include: anatomy and physiology of the conductive system of the heart, genesis of cardiac arrhythmias, pacemakers “their modes, functions, complications, and management of such complications”, and implantable cardioverter defibrillators “their functions, complications, and how to manage these complications”. The anaesthetic management for patients having such devices does not require special technique but the anaesthesiologest should pay good attention to the anaesthetic management of these patients especially those having an underlying heart disease and avoid the anaesthetic implications of such devices.