Increasing use of cocaine among pregnant women has been reported. This study was conducted to determine the prevalence of positive urine toxicologic screens for cocaine and other substances of patients admitted to the Sloane Hospital for Women. Urine samples were obtained from 509 women admitted to the delivery suite. The overall prevalence of cocaine was 10% (n = 51). Cocaine use was 10 times more prevalent in the clinic population (14%) than in the private population, (1.4%). In addition, women whose urine samples were positive for cocaine were more likely to have no prenatal care, previous induced abortions, to be human immunodeficiency virus-positive, and admitted previous use of cigarettes, alcohol, cocaine, and other drugs. Amphetamines were detected in 13% (n = 65) of patients. However, the screens did not distinguish between metabolites of amphetamines and other drugs such as cold medications. The medical history alone predicted only 37% (n = 19) of the cocaine-positive screens and none of the amphetamine-positive screens.