Participants were a subsample of 3 cohorts selected from third graders in 12 elementary schools in 1984, 1985, and 1986. Follow-up of the subsample was conducted at 2-year intervals. The measure of males' pregnancy reports was done at the second young-adult follow-up when the participants were approximately 22 years old. With the exception of sociometric measures, parent and child measures were completed in the home by trained interviewers. The study measured childhood aggression and social preference (status of being liked or disliked by peers), adolescent aggression, alcohol use, involvement with deviant peers, and pregnancy report. The study found that childhood aggression significantly predicted reports on contributions to pregnancies during adolescence. Boys who were stability aggressive across the third through fifth grades were at particularly high risk of reporting getting a girl pregnant. Substance use during adolescence and involvement with deviant peers incrementally added to the prediction of pregnancy reports over and above the effects of childhood aggression. These findings suggest that the precursors for getting a girl pregnant during adolescence can be identified as early as 8 years old. The implications of these findings for preventing adolescent pregnancies are discussed. 3 tables and 71 references