This study examines the overall and relative contributions of a variety of family environment measures to a child's alcohol, marijuana and other drug use, delinquent activity, and dysfunctional methods of coping with problems. The family environment variables tapped aspects of parental behaviors and attitudes, parenting styles, and family harmony and cohesion. Data were collected as part of a prospective, longitudinal study that examined the acquisition and maintenance of a variety of behaviors. Data were gleaned at two points in time, spanning 3-year intervals, from subjects ranging in age from early to late adolescence. In general, alcohol use among the younger subjects was more strongly determined by the use and attitudes of the same sex parent. In contrast, among older subjects, father's alcohol use was important to the offspring's use. While models predicting illicit drug use and the extent of problems related to alcohol and marijuana use fared least well, it was generally found that hostility and lack of warmth on the part of the parents contributed most to these outcomes in subjects. Finally, hostility displayed by both parents helped to determine the incidence of delinquency among sons and the use of dysfunctional coping methods among sons and daughters.