To compare their efficacy and safety, teicoplanin and vancomycin were randomly administered to 32 children for 52 gram-positive bacteremias during malignancy-associated neutropenia (<1000/microl). Patients mainly suffered from hematological malignancies. Twenty-five episodes were treated with teicoplanin (10 mg x kg(-1) x d(-1)) and 21 with vancomycin (40 mg x kg(-1) x d(-1)) plus ceftazidime and netilmicin. Six episodes were treated with teicoplanin because of previous "red man" reaction to vancomycin. Staphylococci (12% Staphylococcus aureus) were isolated from 50 episodes and viridans streptococci from 2. Defervescence on 3rd-4th day occurred in 29/31 (93.5%) teicoplanin-treated and 18/21 (85.7%) vancomycin-treated episodes. All 12 teicoplanin-treated and 13/13 vancomycin-treated episodes with repeat blood cultures on 3rd-4th day showed microbiological response. Two teicoplanin-treated and 3 vancomycin-treated patients required antifungals. Mild renal insufficiency appeared in 5 vancomycin-treated patients that was corrected without drug discontinuation. While both glycopeptides exhibit equal clinical and microbiological efficacy, teicoplanin is less likely to induce allergic reactions or nephrotoxicity in children.