Introduction : False aneurysm of the ascending aorta is a rare complication of aortic valve surgery. It can be associated with significant mortality. Caser report : We report the case of a false aneurysm of the ascending aorta, diagnosed 1 year after aortic valve replacement and a replacement of the ascending aorta by a supra coronary tube for an endocarditis in a patient already operated within the framework of tight aortic stenosis on bicuspidia with dilatation of the ascending aorta. The patient was reoperated with placement of extracorporeal circulation in femoro-femoral associated with selective cannulation of carotids. Peroperatively, we found a dehiscence between the proximal aorta and the Dacron tube that was closed by patches patched by the right trans-auricular approach in circulatory arrest. The bacteriological examination of the specimen was positive for negative Staphylococcus coagulase. The follow-up was simple with a total of 40 days of antibiotic therapy. Conclusion : The ascending aortic pseudoaneurysm is a rare or even exceptional complication of cardiac surgery, the etiology, pathophysiology and natural course of which are still poorly understood. This complication of cardiac surgery remains fraught with high mortality, despite advances in cardiovascular surgery. Each case of ascending aortic pseudoaneurysm is individual and should be managed accordingly. Key-words : Pseudoaneurysm ; valvular surgery; ascending aorta, infection