We investigated the combination of teicoplanin and ceftriaxone for its bactericidal activity against Staphylococcus aureus, Haemophilus influenzae type b and Streptococcus pneumoniae isolated from bone and joint infections in children. An increase in bactericidal activity was observed against isolates of S. aureus and H. influenzae when the antibiotics were tested at fractional MICs whereas indifference was observed at their MICs. Similar results were obtained at fractional MICs against S.pneumoniae, but the bactericidal activity fell by more than 1 x log 10 cfu/mL when the antibiotics were tested at or above their MICs.