Vancomycin is effective against most multiply resistant staphylococci, organisms that are becoming increasingly important in clinical medicine. Reported experience with vancomycin therapy in pediatric patients is limited. In this study vancomycin was administered intravenously to 33 patients whose ages ranged from one week to 16 years and who had suspected or proved infections caused by either Staphylococcus aureus or Staphylococcus epidermidis. The spectrum of staphylococcal infections included skin and soft-tissue infections and abscesses, osteomyelitis, pneumonia, shunt infections, endocarditis, and septicemia. All 29 patients with bacteriologically proved staphylococcal infections responded to vancomycin therapy. Peak and trough concentrations of vancomycin in serum produced satisfactory bacteriostatic and bactericidal titers against the infecting pathogens. In an anephric patient hemodialysis removed only negligible amounts of vancomycin. The amount of vancomycin that penetrated into ventricular fluid of 10 patients with shunt infections ranged from 7% to 37% (mean, 18%) of serum concentrations. One case of phlebitis and one case of transient elevation of serum levels of aspartate amino transferase were observed. No renal or otologic damage was detected in any patient. Adequate dilution of the drug, intravenous administration during 1 hr, and monitoring of the concentration in serum of patients undergoing long-term treatment and/or with impaired renal function minimize the likelihood of side effects. Vancomycin is an effective and safe agent for treatment of staphylococcal infections in pediatric patients.