The patient was a 59-year-old man who had undergone aortic valve replacement with a mechanical valve for aortic stenosis eight years ago. Six months ago, he developed complete atrioventricular block and underwent pacemaker implantation. One day before admission, he presented to a local clinic with complaints of dyspnea and chest pain. Suspecting acute myocardial infarction, he was referred to our hospital for further evaluation and was subsequently admitted. On admission, he exhibited fever and elevated inflammatory markers. Transthoracic echocardiography and computed tomography revealed vegetations on the prosthetic valve and an annular abscess with aneurysmal dilatation of the sinus of Valsalva. Based on these findings, prosthetic valve endocarditis was diagnosed, and semi-urgent surgery was performed. Intraoperatively, numerous vegetations were found attached to the prosthetic valve annulus, and the annular abscess had extensively invaded the myocardium circumferentially. Aneurysmal dilatation of the sinus of Valsalva was observed, especially around the left and right commissures. After debridement of the abscess cavity, it was determined that Bentall procedure was not feasible due to extensive annular destruction and fragility of the surrounding myocardial tissue. Therefore, we opted for a root reconstruction using the “graft insertion technique” as described by Nakamura et al. A 5-cm length of tube graft was inverted and inserted from the aortic root into the left ventricular outflow tract (LVOT). Nine mattress sutures using 3-0 polypropylene with pledgets were placed from inside the graft through the LVOT, with external reinforcement using a Teflon felt strip, followed by continuous suturing for added security. The intraventricular portion of the graft was pulled out through the LVOT and trimmed. A preconstructed composite graft was then anastomosed to the trimmed end. The right coronary artery was reimplanted using the button technique. The left coronary artery was injured during dissection of adhesion and could not be reimplanted; therefore, a bypass from the great saphenous vein to the left anterior descending artery was performed. Despite the loss of healthy annular tissue due to complete debridement of the infected valve and myocardial abscess, the reconstruction of the aortic root was successful without the need for additional hemostatic sutures. The “graft insertion technique，” though not yet widely established, offers a valuable approach for reconstructing severely damaged and fragile aortic roots in the setting of prosthetic valve endocarditis. It allows for safe and reliable surgical repair even in challenging anatomical conditions.