There is some debate in the resuscitation literature about whether training lay people in the use of an Automatic External Defibrillator (AED) is actually necessary. Certain models of AED implementation have successfully been used where no formal training has been provided. This paper reports on a qualitative, interview-based study of lay people who had been trained to use an AED. The data suggests that the training event, and especially the faceto-face contact with the trainers, plays an important part in persuading people to trust the AED, and to use it, if and when an emergency occurs. Thus the training event may have a value in addition to teaching lay people the skills of using an AED.