Thirty-three rabbits, (12 in the control group and 21 treated, 5 with teicoplanin, vancomycin and cloxacillin-gentamycin and 6 with cloxacillin alone) with methicillin-sensitive Staphylococcus aureus (MSSA) experimentally induced endocarditis were studied to evaluate the efficacy of teicoplanin and its comparison with cloxacillin, vancomycin and cloxacillin-gentamycin. The rabbits were treated during three days. Mortality, blood cultures at 48 and 72 hours and the number of colonies forming units per gram of vegetation were then evaluated. There was statistically significantly differences between the control group and the 4 treated groups in respect of mortality (p less than 0.001), and blood culture's negativity at 48 and 72 hours (p less than 0.001), but not among the various groups of treatments. The CFU number of the vegetations were also significantly different between control and treatment groups (p less than 0.001). Cloxacillin and the combination cloxacillin-gentamycin lowered the CFU number more than teicoplanin and vancomycin (p less than 0.005). These results, allowed us to conclude than teicoplanin may be used as an alternative of standard treatments in infective endocarditis due to MSSA.