Based on the recognition that interleukin-6 (IL-6) is produced early in infection, IL-6 determinations have been used to identify infants with early onset bacterial sepsis. This study intended to assess the value of IL-6 in maternal, cord and infant peripheral blood as an index of sepsis, and examine the relationships of its values in mother and infants. The population consisted of 17 mother/infant pairs at high risk for neonatal infection. Eight of these infants had clinical signs of possible sepsis. Cord blood IL-6 levels in infants of mothers considered to be noninfected were lower than those born to women with chorioamnionitis. There was also a positive correlation between maternal and cord blood IL-6 values. There were no differences in maternal blood IL-6, whether they had infections or not. Also, peripheral infant blood obtained after birth did not differentiate between those born to women with or without chorioamnionitis, nor did it correlate with maternal blood IL-6 levels. Clinical symptoms of the infants did not correlate with either cord or peripheral blood IL-6 values. Although maternal prepartum treatment with antibiotics and/or steroids may influence their own and their infants' blood IL-6 levels, there is insufficient evidence to consider low infant blood IL-6 level a reliable predictor to rule out early newborn sepsis.