Automated External Defibrillators (AED) are becoming more prominent in public locations within the mainstream of our society. They are marketed as providing the ability for a broader range of people, beyond clinicians and community emergency medical services personal, to successfully defibrillate a person in cardiac arrest. The objectives of this study were to determine whether or not a member of the general population, without previous exposure to an AED, could successfully operate an AED, thus delivering the necessary shock in ventricular fibrillation arrest. In addition, we analyzed the relationship between health care training and the time required to defibrillate a patient using an AED and investigated the overall success of operating an AED with respect to health care training. Utilizing an AED trainer, we conducted a timed trial study of five subject categories (general population; first-year dental students; third-year dental students; dentists, hygienists, and nurses; and anesthesiologists and surgeons) as each operator attempted to defibrillate a mannequin (n=50). Their times, success in defibrillation, and comments were recorded. The general population group experienced an 80 percent failure rate, while the other groups showed an inverse relationship between failure rates and the amount of health care training. Overall, only 58 percent of the subjects successfully performed the defibrillation with the AED. Operator speed in relation to the amount of health care training showed another inverse relationship as times decreased from group one (general population) to group five (anesthesiologists and surgeons). The findings suggest that prior exposure to an AED leads to a greater number of successful defibrillations. It remains unclear at this time as to whether a member of the general population can successfully operate an AED.