S. suis causes severe infections in pigs, such as meningitis, arthritis, endocarditis and septicemia, which are associated with important economic losses in the swine industry [9]. Unfortunately, S. suis is becoming increasingly resistant to several antibiotics, more specifically to macrolides, tetracyclines and lincosamides [23]. Strategies to overcome this problem are to look for new antimicrobial agents as well as to use combinations of antimicrobial agents. Bacteriocins have been proposed to represent promising alternatives for the treatment of diseases caused by pathogenic bacteria [13]. In this study, we aimed to obtain in vitro data supporting the potential of nisin, a lantibiotic licensed as a food preservative, for preventing swine infections caused by S. suis and to evaluate synergy between this bacteriocin and conventional antibiotics.