A case-control study was conducted 1) to determine whether maternal prenatal drug consumption increases the risk of neuroblastoma in the child and, if so, 2) to see if the size of the risk depends on whether the case is inherited or sporadic. Mothers of children with newly diagnosed neuroblastoma (n = 101) were compared with mothers of children newly diagnosed with other forms of childhood cancer (n = 690). Cases and controls were selected from the population of childhood cancer patients at St. Jude Children's Research Hospital, Memphis, Tennessee, between 1979 and 1986. The patients' mothers were interviewed to ascertain their prenatal medication, alcohol, and tobacco consumption patterns. Unconditional logistic regression models were used to adjust for maternal age at birth, patient age at diagnosis, race, social class, exposure to x-ray, miscarriage, and other confounding variables. Adjusted odds ratios were estimated for the total sample and for subgroups that had a higher probability of containing inherited cases. Drugs associated with neuroblastoma case status include diuretics for hypertension (odds ratio (OR) = 4.1, 95 percent confidence interval (CI) 1.0-16.9), tranquilizers (OR = 2.1, 95 percent CI 1.1-4.3), nonprescription pain relievers (OR = 1.9, 95 percent CI 1.1-3.1), and cigarettes (OR = 1.9, 95 percent CI 1.1-3.2). The odds ratios for maternal prenatal drug consumption for the group with inherited cases and the total sample were approximately the same. This equality is inconsistent with predictors based on Knudson's two-stage model of carcinogenesis.