Infective endocarditis (IE) caused by Aerococcus urinae is rare. The true incidence rate of this pathogen is likely underestimated as this is easily misidentified as Staphylococci or Streptococci. It is also associated with increased risk of complications such as systemic emboli. Aerococcus usually affects elderly males with underlying urological conditions. Here we present a case of IE with this rare Aerococcus urinae in a young man with a bioprosthetic aortic valve, despite negative urine cultures.