Liver abscesses are common in Taiwan. Although Gram-negative Klebsiella species are the most common pathogens associated with liver abscesses, cases of liver abscess with infective endocarditis (IE) are rare. Herein, we report the case of a liver abscess caused by Klebsiella pneumoniae in a patient who presented with consciousness disturbance after 7 weeks of antibiotic treatment. In conjunction with the brain magnetic resonance imaging findings, cerebrospinal fluid analysis revealed septic emboli. Large aortic valve vegetation, which was not initially evident, was identified during follow-up transthoracic echocardiography and later progressed into aortic root abscess formation. Therefore, the patient received porcine aortic valve replacement, from which he recovered well. We highlight the importance of prompt detection of concomitant IE, particularly in patients with degenerative aortic valves.