Ventricular tachycardia and ventricular fibrillation are the most important causes of sudden cardiac death (SCD), particularly in those with structural heart disease and reduced left ventricular function. It is important to distinguish ventricular tachycardia from supraventricular tachycardia. A wide spectrum of ventricular arrhythmias exists, from those where the heart is structurally normal to those with structural heart disease. Each entity has a distinctive pathophysiology, treatment plan and prognostic outcome. Treatment modalities include simple beta-blockade to implantation of implantable cardiac defibrillator and ablative approaches. In general, those ventricular arrhythmias associated with a structurally normal heart are more benign than those associated with structural heart disease.