One hundred forty-two low income women were interviewed postpartum to determine their attitudes regarding the potential effects of a punitive law on the behavior of substance-using pregnant women. The convenience sample was primarily black (85.2%) and single (81%) and 14.8% admitted use of illicit drugs during pregnancy. A goodness-of-fit chi-square analysis revealed that subjects believed a punitive law would be a significant deterrent to substance-using gravida seeking prenatal care, drug testing or drug treatment (P < 0.01). Comments indicated that substance-using pregnant women would 'go underground' to avoid detection and treatment for fear of incarceration and loss of their children.