A 46-year-old woman with sudden on set strong right flank pain was transferred to our hospital with the diagnosis of right renal infarction. Cardiac ultrasonography revealed a vegetation on the posterior cusp of the mitral valve, and the renal infarction was thought to be caused by renal artery embolism from infective endocarditis. Since the vegetation remained after antimicrobial therapy as conservative management, the patient was surgically treated by mitral annuloplasty. It has been known that infective endocarditis can cause renal infarction. Infective endocarditis requires immediate and adequate treatment because of high mortality. Therefore, the appropriate diagnosis of infective endocarditis is needed for patients with renal infarction without any other disorder causing renal infarction.