With an ageing population an increasing number of patients with a pacemaker or implantable cardioverter defibrillator will present at radiotherapy units due to malignancy. Two separate questionnaires concerning routines of departments treating this population were sent to Danish implanting cardiology centers and to radiotherapy departments. Differences in the handling of these patients were found. Removal of the devices and monitoring of the patients is assessed on a highly individual basis. In the absence of updated official guidelines, departments treating these patients should produce local instructions.