Despite the general acceptance of implantable cardioverter defibrillator (ICD) therapy [including cardiac resynchronization therapy defibrillator (CRT-D)] among cardiologists, there has been some recent concern about potential harm associated with ICDs, particularly related to quality of life and possible adverse effects of ICD shocks. These and others undeniably constitute complications of ICD therapy paper. However, the evidence from multiple ICD/CRT-D trials, which take into account complications on the one side, and benefits on the other, speaks strongly in favour of patients receiving net benefit, rather than harm. And this is true for (i) prognosis, (ii) effects of shocks, and (iii) quality of life. Moreoveraddressing specifically the complications aspectsthere have been major advances, both in the technology of the systems and in physician practice, which have put major focus on minimizing shocks (appropriate and inappropriate) in favour of antitachycardia pacing. In addition, the tendency is that more and more of such patients receive devices incorporating cardiac resynchronization pacing, now proven to delay and/or minimize heart failure. There is now a large body of evidence, particularly in recent years with improved technology, that, rather than oharm', the ICD/CRT-D provides substantial protection for appropriately selected patients.