The most significant arrhythmological differences between the two sexes are reported. In females, the “basal” sinus frequency is generally higher than in males. Inappropriate sinus tachycardia is an arrhythmological condition almost exclusively of the female sex. In women, the incidence of AV nodal reentry tachycardia is higher than in men, as is the incidence of acquired long QT syndrome and—consequently—the risk of torsade de pointes. In women affected by atrial fibrillation, the risk of ischemic stroke is higher than in men. Finally, the incidence of sick sinus syndrome is higher in women than in men. In men, the incidence of atrioventricular reentry tachycardia involving an accessory pathway, atrial fibrillation in athletes, distal atrioventricular block, and sudden cardiac death is higher