The frequency of positive cord blood rapid plasma reagin (RPR) tests among newborns at an inner city hospital and associations with maternal cocaine use, prenatal care, and adequacy of syphilis therapy were retrospectively assessed. The incidence of positive cord blood RPRs increased from 1.1% of all live births in 1985 to 3.4% in 1988. In 1987, 98 babies were born with positive cord blood RPRs; 86 of their charts were available for review. Four infants had false positive RPRs, and one patient delivered twins, leaving 81 mothers who could be evaluated. Almost 37% of these patients had had no prenatal care. More than 55% had inadequate or not therapy for syphilis. Of these, only 17.4% had prenatal care. Slightly more than 40% of patients acknowledged using drugs during pregnancy, 87.9% of whom used cocaine. Among the patients who used drugs, 75.8% received no prenatal care, in contrast to 10.4% of mothers who did not use drugs (p less than 0.001). It appears that drug use, particularly use of cocaine, is associated with low levels of utilization of prenatal services and inadequate therapy for syphilis. This may lead to increased risk of congenital syphilis in newborns.