We investigated whether decrements in neonatal neurodevelopment, as determined by the Brazelton neonatal behavioral assessment scale (BNBAS), were associated with in utero exposure to dichlorodiphenyltrichloroethane (DDT): p,p'-dichlorodiphenyl trichloroethane (p,p'-DDT), o,p'-dichlorodiphenyl trichloroethane (o,p'-DDT) and p,p'-DDT's primary breakdown product p,p'-dichlorodiphenyl dichloroethylene (p,p'-DDE) (heretofore collectively referred to as DDT/DDE). Our subjects were a birth cohort of 303 infants whose mothers were low-income Latinas living in the Salinas Valley, an agricultural community in California. We assessed neonates < or =2 months old using the seven BNBAS clusters (habituation, orientation, motor performance, range of state, regulation of state, autonomic stability, and reflex) and examined performance in relationship to DDT/DDE measures in maternal serum samples collected during pregnancy. We did not find any detrimental associations between in utero DDT/DDE levels and neonatal performance on the BNBAS. In this same cohort, we previously demonstrated that exposures to DDT/DDE were related to decrements in neurodevelopment at 6-24 months of age. The failure to observe effects on the BNBAS in these same children may be due to limited sensitivity of a single BNBAS assessment or a delay in the manifestations of neurodevelopmental effects of DDT/DDE until after the neonatal period.