Whether zolpidem crosses the placenta in humans is unknown. A 30-year-old Caucasian woman with a history of zolpidem abuse underwent spontaneous vaginal delivery at 38 weeks' gestation. Total fetal exposure to zolpidem was unknown, but it was estimated to be at least 1000 mg over at least 1 month. Typical peak plasma concentrations after a single 5- and 10-mg dose of zolpidem are 29-113 ng/ml (mean 59 ng/ml) and 58-272 ng/ml (mean 121 ng/ml), respectively. Cord blood was sampled for zolpidem, with a result of 41 ng/ml. Despite the presence of zolpidem in the cord blood sample, the neonate was active and alert after normal delivery. No withdrawal symptoms were noted, and the mother and neonate were discharged home after 48-hour observation. This case report indicates that zolpidem crosses the human placenta, as was exemplified with cord blood sampling. The drug should therefore be used during pregnancy only if clearly necessary.