This study explored nurses' confidence and competence in preparing patients for having an implantable cardioverter defibrillator implanted and for life at home after discharge. Whilst research has identified various physical and psychosocial effects to patients and their partners associated with device implant and subsequent lifestyle adjustments, no research has explored nurses' knowledge of the device or these effects. A survey was designed using a purposive sample of 152 nurses from cardiology areas in four large teaching hospitals and a 28-point postal questionnaire to explore knowledge of the device and its impact. Most subjects were not confident in their abilities to prepare patients for implant or life at home after implant. Knowledge of the device and its effects appeared poorly understood by all nurses, irrespective of additional qualifications, length of time since qualifying or area of work. Many participants were aware of the poor knowledge level of nurses and identified it as a weakness in current care practices. Lack of understanding may impair preparation of patients for implantation of or for living with an implantable cardioverter defibrillator, and feasible strategies to change this situation will require careful consideration and further investment.