RESUMEN
Streptococcus bovis (S. bovis) organisms, part of the gastrointestinal normal flora are gram-positive group D streptococci that may be misidentified as enterococci or viridans streptocci. The most important clinical infections caused by S. bovis are bacteremias and endocarditis. S. bovis causes 27% of the episodes of streptococcal native valve endocarditis. Besides, it has been known that there is a association between S. bovis bacteremia and underlying malignancy of the colon. After this association was demonstrated by Klein in 1977, many cases have been reported. But, it is not clear if S. bovis plays an etiologic role in carcinoma of colon or merely a marker for the disease and cases from Korea have rarely been reported. Therefore, we report one case that two synchronous colon cancers, the one on ascending colon and the other on sigmoid colon is accompanied by S. bovis endocarditis.