• Samples of meconium from 28 neonates born to women suspected of drug abuse were tested for drugs of abuse (ie, cocaine, morphine, codeine, and marijuana). In each case, testing of urine from the mother, the newborn, or both had been ordered by the attending physician because of suspected maternal drug abuse. Seventeen (61%) of 28 meconium samples tested positive; 28 (60%) of 47 urine samples were positive. Meconium test results were concordant with the results of maternal or newborn urine testing in 24 (86%) of the 28 cases. In three cases, meconium was positive for cocaine when newborn urine was negative; in one case, meconium was negative when maternal urine was positive for cocaine. Compared with the combination of maternal and newborn urine testing, meconium testing had an 82% positive predictive value (14/17) and a 91% negative predictive value (10/11). Collection of meconium is simpler and more reliable than collection of urine, and testing of meconium was easily incorporated into routine procedures at a busy commercial laboratory. Meconium is a useful sample for drug detection in newborns.