Data from the National Longitudinal Study of Youth (NLSY) were used to examine factors related to adolescent behavior problems, smoking, and delinquency. This study focuses particularly on the factors in an adolescent s immediate environment such as family, school, peers, and neighborhood (i.e. the microsystems) for the identification, prevention, and early intervention of adolescent behavior problems, smoking, and delinquent behavior. Both African American and Caucasian American adolescents between the ages of 13 and 17 for whom data were available in the NLSY were included in this study (N=788). Results indicate that delinquent peer pressure and negative attitudes toward school are important determinants of behavior problems, smoking, and delinquency of American adolescents. Differences between African American and Caucasian American adolescents are highlighted.