An epidemiologic study of urban-dwelling children aged 8-10 years in Baltimore, Maryland, was undertaken to test the hypothesis that close monitoring and supervision by parents might signal a reduced risk of drug use in the elementary school years. Drug use, monitoring by parents, peer drug use, and other suspected risk factors for early drug use were first assessed in 1989, identifying 947 children with no prior history of drug use. One year later, 4.2 percent of these children were found to have started using alcohol, tobacco, or other drugs on their own for the first time during the follow-up observation interval. Risk of starting drug use was higher for children with lower levels of parent monitoring (relative risk = 4.39, 95% confidence interval 1.48-13.0). In addition, for children with declining levels of parent monitoring, there was an increased risk of starting to use drugs on their own.