The implantable cardioverter defibrillator (ICD) is today an indisputable evidence-based treatment for cardiac sudden death both in primary and secondary prevention. However many clinical conditions that would represent an indication to ICD implantation, according to guidelines, may be potentially reversible or may be accompanied by temporary contraindications to the implant. Moreover transvenous cardioverter defibrillator implantation still carries a not negligible risk of complications both acutely and at follow-up. The Wearable Cardioverter Defibrillator and the Subcutaneous Defibrillator are two recently developed technologies that can potentially overcome the aforementioned limitations of traditional transvenous ICDs. This review will discuss the main aspects of these 2 technologies, the data coming from clinical experiences and future perspectives.