Sustained or recurrent tachyarrhythmias are an important cause of fetal morbidity and mortality. The most common type of fetal tachycardia is supraventricular tachycardia, followed by atrial flutter. Other tachyarrhythmias such as atrial ectopic tachycardia, junctional reciprocating tachycardia and ventricular tachycardia are rare in fetal life. Appropriate management depends on accurate diagnosis. Ultrasound is essential for a precise knowledge of the electrophysiologic mechanism underlying the arrhythmia, and to examine the hemodynamic impact of the tachycardia both before and after the antiarrhythmic therapy. The information concerning the type of fetal tachyarrhythmia is usually inferred from the fetal heart rate, and the relationship between atrial and ventricular events as demonstrated by M-mode echocardiogram and Doppler flow signals. The decision to initiate pharmacological intervention depends on several factors and must be weighed against possible maternal and fetal adverse effects of the antiarrhythmic drugs. Several options are available when facing with a fetus with a tachycardia, ranging from close observation without therapy to direct administration of antiarrhythmic drugs into the fetal circulation. Although there are many series in the medical literature reporting that fetal tachycardias can be suppressed successfully using antiarrhythmic drugs given to the mother, currently there is no global consensus concerning the precise management of these fetuses. Certainly, the ultimate decision on the management of fetal tachycardias will vary from center to center. In this paper we will analyze our experience in the diagnosis and management of fetal tachyarrhythmias together with a review of modern literature in this topic.