The in vitro activity of antibiotic combination of teicoplanin and gentamicin (or netilmicin) and teicoplanin and cephalotin on Staphylococcus aureus was evaluated using the checkerboard method and time-kill curves. With few exceptions neither antagonism nor synergism was seen for the combination of teicoplanin and aminoglycosides using the checkerboard method. Using time-kill curves synergism was often found for the combination of teicoplanin and netilmicin (even at sub-minimal inhibitory concentrations of netilmicin) and for the combination of teicoplanin and cephalotin. No antagonistic interactions occurred.