This paper reports the diagnosis and treatment process of a patient with infective endocarditis caused by Aerococcus urinae (A. urinae). The incidence of A. urinae endocarditis is low, research data from large number of specimens are lacking, and the clinical manifestations lack specificity. Multiple detection methods, including 16S ribosomal RNA gene sequencing, can assist in diagnosis. The susceptibility factors for this disease include being male, advanced age, and previous urinary tract diseases. This case was treated with a combination of β-lactam and aminoglycoside agents, and the symptoms relieved. However, vegetations did not shrink after antimicrobial treatment for 4 weeks, disease condition became serious and the valve were damaged even worse. Surgical treatment was finally performed and the patient recovered.