The purpose of this paper is to describe the authors' approach to the diagnosis and treatment of aortic intimal dissection encountered as a complication of the arterial cannulation procedure employed routinely during neonatal venoarterial ECMO. A case report is provided. Recognition of this entity clinically was based on diminished pulses in the lower extremities with dampening of an umbilical arterial catheter transduced pressure wave form one day after decannulation from ECMO. Confirmation was achieved using a phased array echocardiographic Doppler system (ECHO). Successful surgical repair was achieved under deep hypothermic circulatory arrest on cardiopulmonary bypass, with partial resection of the affected aorta, and with sutures placed through the intimal flap and the aortic wall. Aortic continuity was established by end-to-end anastamosis posteriorly, and the aortic arch was reconstructed anteriorly with an aortic homograft. To the author's knowledge, this is the first case of this problem being identified and treated in an ECMO treated neonate.