Medical treatment of fetal tachycardias has substantially improved neonatal outcome over the past years. Digitalis has been often used as first-line therapy in these cases, and more recently the use of several newer agents have been reported. We present four cases of fetal tachycardia with a favorable neonatal outcome after successful treatment with digitalis. Rapid transplacental digitalization appears to be an effective and reliable treatment option for fetal tachycardia, particularly in non-hydropic fetuses. In hydropic fetuses, however, digitalis alone appears to be less effective and administration of a second drug is usually needed.