The activities of teicoplanin and vancomycin against 362 coagulase-negative staphylococci were determined by an agar dilution method. At the 4- and 32-micrograms/ml breakpoint levels of the National Committee for Clinical Laboratory Standards, 23.2% of the strains were intermediate and 1.7% were resistant to teicoplanin, in contrast to less than 0.3% intermediate to vancomycin. Resistant strains belonged to the species Staphylococcus epidermidis (74%) and S. haemolyticus (19%).