In recent years major advances have been made in the recognition and treatment of candidates to sudden cardiac death. These advances include very sophisticated diagnostic and therapeutic techniques, such as genetic testing and the implantable cardioverter-defibrillator, new knowledge coming from large multicenter trials, particularly about the poor efficacy of so-called "antiarrhythmic" drugs, but also very important advances have been made in improving the diagnostic value of simple techniques such as the twelve-lead electrocardiogram. In this article six different electrocardiographic patterns associated to sudden cardiac death are described. Some patterns, like left ventricular hypertrophy or low voltage in the limb electrocardiographic leads, are frequent and the incidence of sudden death in these patients is relatively low, although clearly higher as compared to individuals with a normal electrocardiogram. On the other hand, other patterns which are rarer (like the long QT syndrome or the syndrome of right bundle branch block and ST segment elevation in V1-V3) are associated to a very high rate of sudden death. Because sudden death can be prevented in many cases, every doctor should be able to recognize these types of electrocardiograms.