Sudden death accounts for about 15-20% of all natural fatalities in the industrially developed world. Most of the victims have a substrate of extensive myocardial injury caused by coronary heart disease, cardiomyopathy and hypertensive heart disease. In most cases, the immediate cause of death is triggered by ventricular tachycardia which degenerates into ventricular fibrillation. Changes in myocardial electrical properties may be critically modified by ischemia, imbalance in the autonomic nervous system, electrolytic disorders, and haemodynamic factors. We review the causes of sudden cardiac death, giving special attention to the effect of beta-adrenoceptor blockade as a preventive measure.