Intermittent functional closure of a patent duct has been reported both clinically and echocardiographically. We describe the case of a 6-year-old with intermittent complete closure of a patent duct occurring during attempted transcatheter closure. Recurrence of clinical and echocardiographic signs prompted restudy. A patent duct of moderate size was demonstrated and successfully occluded by coil embolization. The interventional aspects of this unusual condition are discussed.