Each year at least 300,000 people in the United States and 8000 to 10,000 people in Switzerland suffer from out-of-hospital cardiac arrest, mostly due to ventricular fibrillation. Early defibrillation provides definitive treatment for most of cardiac arrest victims. Semi-automatic external defibrillators are easy to handle devices allowing to deliver an early electric shock and can be successfully used by lay people following minimal training. Newer strategies of defibrillation designed to respond faster to out-of-hospital cardiac arrest, including public access defibrillation, as well as improvement of each link of the chain of survival appears as the best strategy for the management of out-of-hospital cardiac arrest.