A rare case of left ventricular outflow tract (LVOT) pseudoaneurysm complicated with prosthetic valve endocarditis was reported herein. A 78-year-old male previously underwent aortic valve replacement (AVR) with a bioprosthesis. Four years after the initial operation, he presented with prolonged high fever and bloody sputum. Multi-detector row computed tomography (MDCT) clearly showed LVOT pseudoaneurysm originating from a subvalvular fibrous region. The patient underwent re-AVR and repair of pseudoaneurysm. The postoperative course was uneventful, and the patient recovered good condition.