Lactococcus garvieae is a human opportunistic pathogen with low virulence, but it is a well-known pathogen in aquaculture. A total of 21 human infections have been reported in the literature, mostly endocarditis. Automated methods can wrongly identify this microorganism as Enterococcus spp with a non-standard phenotype, leading to an underestimation of the incidence of this infection. The route of infection could be the ingestion of raw fish, grilled fish or fresh dairy products. We describe the first case of L. garvieae mitral valve endocarditis in Italy, in a patient with mitral valve repair with autologous pericardium, mechanic prosthetic aortic valve and colonic diverticulosis.