Many researchers have studied predictors of adolescent substance use. One important predictor of substance use is the quality of the parent-child relationship. Most studies address the parent-child relationship unidimensionally. This study hypothesized that it is not use of a particular substance that can be predicted from a poor parent-child relationship, but use of the most advanced substance that children are at risk to use at that developmental period. This study examined risk to use drugs, rather than actual drug use, as the outcome measure and explored the association between components of the parent-child relationship and risk for substance use 1 year later among nonusing young adolescents. Subjects were seventh graders and their participating parents, including 272 nonusers of tobacco and 437 nonusers of marijuana at the beginning of the study. Factor analysis identified the parental relationship and risk-to-use factors, which provided constructs for causal modeling. Analyses were conducted separately for tobacco and marijuana use. The parental relationship constructs did not predict later use of tobacco. One parental relationship construct, emotional closeness, predicted later risk to use marijuana. Emotional closeness with parents, including physical signs of affection, appeared to serve a role in preventing young adolescents from later marijuana use. (Author/ABL)