An association between high DDT cord blood levels and prematurity was investigated. Pregnant women with good health and nutritional condition, negative history of past occupational exposure to DDT and absence of recent exposure to DDT were investigated as well as their appropriate for gestational age neonates. A total of 54 maternal-infant pairs were studied and divided in two groups: A-term deliveries (30 pairs), B-preterm deliveries (24 pairs). There was no difference in DDT blood levels between pregnant women of both groups. There was, however, a significant difference in DDT cord blood levels between term and preterm infants, as well as between maternal and neonatal blood levels in both groups. DDT cord blood levels correlated negatively with infants' birth weights. We suggest that there is an association between prematurity and high DDT cord blood levels in a non-occupationally exposed population and the amount of fetal adipose tissue is an important factor determining the cord blood level of this pesticide. We cannot rule out a cause-effect association between high DDT cord blood level and prematurity.