Lactococcus garvieae is considered to be a rare pathogen with low virulence in humans. We herein experienced an unusual case of multi-valve infective endocarditis caused by L. garvieae in an elderly woman who had undergone bioprosthetic mitral valve replacement due to severe mitral stenosis with rheumatic etiology. The patient was successfully treated with cardiac surgery after teicoplanin antimicrobial therapy failure followed by ceftriaxone treatment. L. garvieae was confirmed as the pathogen through 16S rRNA sequencing. To the best of our knowledge, this is the first case to indicate an effective treatment for infective endocarditis caused by L. garvieae in the Republic of Korea.