To assess chlorhexidine absorption and skin tolerability in premature infants, following skin antisepsis with 2% aqueous chlorhexidine gluconate (CHG) prior to peripherally inserted central catheter (PICC) placement. Neonates less than 32 weeks gestation had skin cleansed with CHG prior to PICC placement. CHG concentrations were measured on serial blood samples. Skin integrity was evaluated for 2 weeks after CHG exposure. Twenty infants were enrolled; median gestational age was 28 2/7 weeks (range 24 3/7 to 31 4/7). Ten infants had detectable serum chlorhexidine concentrations (range 1.6 to 206 ng ml(-1)). Seven of these infants had their highest serum concentration 2 to 3 days following exposure. No CHG-related skin irritation occurred in any infant. CHG was detected in the blood of preterm infants receiving CHG skin antisepsis for PICC insertion. Highest serum concentrations occurred 2 to 3 days after exposure. Further investigation is needed to determine the clinical relevance of CHG absorption in preterm infants.