Background: The antenatal diagnosis of fetal arrhythmias helps direct medical management, which may include intra-uterine therapy. Ectopic atrial tachycardia is an unusual arrhythmia in children, and we know of no previous reports of antenatal diagnosis of this particular arrhythmia.Case: The diagnosis of fetal ectopic atrial tachycardia was suggested by the monitor tracing during labor and was subsequently confirmed by the postpartum behavior of the arrhythmia and its electrocardiographs characteristics.Conclusion: Ectopic atrial tachycardia, although uncommon, should be considered in the differential diagnosis of fetal tachycardias. The fetal monitor tracing may be useful in making this diagnosis antenatally, which may help to direct management both before and after birth.