Perinatal atrial flutter is a potentially lethal arrhythmia. Management of this disorder is difficult and controversial. Fetal atrial flutter is a serious and life threatening rhythm disorder particulary when it causes hydrops; it may be associated with fetal death or neurological damage. Although the initial episode of flutter may be difficult to control, recurrence of atrial flutter after successful resolution of the arrhythmia seems highly unlikely and long-term prognosis is excellent. We experienced a case of a atrial flutter diagnosed in utero at 38+6 weeks' gestation by fetal cardiac echocardiography. He was treated with maternal digoxin, but he continued to have atrial flutter until delivery. Restoration of sinus rhythm occured with propafenone therapy in this patient after failure of initial digoxin therapy and direct current cardioversion.