The objectives of this study were to characterize the pharmacokinetics and determine the cerebrospinal fluid concentrations and safety of intravenous rifampin in pediatric patients undergoing shunt placement. Nine patients (mean age 5.6 y) received a single dose of rifampin, 20 mg.kg-1, administered intravenously 1 h prior to surgery. The peak serum concentrations ranged from 13.5-26.7 micrograms.ml-1; cerebrospinal fluid concentrations ranged from 0.12-3.0 (mean: 1.4) micrograms.ml-1. The mean total clearance, apparent distribution volume, and elimination half-life were 0.29 l.kg-1.h-1, 1.11.kg-1, and 2.8 h. The concentrations of rifampin achieved in the cerebrospinal fluid exceeded the minimum inhibitory concentrations by 100- to 1000-fold against Staphylococcus epidermidis. However, 5 of 9 patients developed cutaneous reactions during intravenous rifampin prophylactic therapy. Because of the high frequency of adverse effects and more than adequate rifampin concentrations achieved in the cerebrospinal fluid, rifampin doses lower than that used in this study may be evaluated in future studies.