Recently, there have been some reports that cone reconstruction can be performed in the repair of Ebstein's anomaly with acceptable result on a child. On an adult with Ebstein's anomaly, optimal surgical indication and choice of the operative procedure are controversial. A man in his seventies was diagnosed with Ebstein's anomaly incidentally during preoperative examination of severe aortic regurgitation. We performed aortic valve replacement and cone reconstruction, because his tricuspid regurgitation was moderate. There was no severe complication and he was discharged. No sign of recurrence have been observed after 4 months follow up. We present a case in which cone reconstruction and aortic valve replacement were successfully performed on an adult patient diagnosed with Ebstein's anomaly and severe aortic regurgitation.