The anatomical and tissue changes caused by hypertension are responsible of the higher incidence of atrial and ventricular arrhythmias as compared to normal population. Hypertension, when associated with atrial fibrillation, becomes an important risk factor for systemic embolism. Atrial dilatation and/or fibrosis because of haemodynamic overload due to left ventricular hypertrophy are the arrhythmic substrate. The higher incidence of ventricular arrhythmias is related to left ventricular hypertrophy. Ventricular premature beats, frequent and/or polymorphic in most of the cases, and short runs are the usual picture. Sustained ventricular tachycardia is seldom documented. The substrate is created by hypertrophy itself, resulting in conduction disturbances favoring reentry. Associated myocardial ischemia plays an important role in the genesis of ventricular arrhythmias. Left ventricular hypertrophy is associated with an increased incidence of total cardiac death and sudden death. Ventricular arrhythmias are suggested to be a poor prognostic factor. The aim of this article is to offer a simplified review of the meaning of cardiac arrhythmias in the hypertensive patient, and to give some clues to the practical approach in the clinical setting.