Survival to discharge following a cardiac arrest is dependent on rapid and effective basic and advanced life support. Paramount to a raphid response is access to sufficiently trained health care providers, who have a duty to perform basic life support and initiate early defibrillation. In hospitals, defibrillation remains the domain of specially prepared staff and the type of defibrillator used might be crucial to rapid and effective defibrillation. The advent of automatic external definrillators has increased the range of people who can use a defibrillator successfully. For nurses, arguably a lack of familiarity about the benifits of and the use of automatic external defibrillators are the greatest barriers to nurse-initiated defibrillation programmes. This paper explores the use of automatic external definrillators, their relationship to the associated defibrillator waveforms and the benifits of their use by registered nurses within the hospital setting.