Data were obtained from the first follow-up survey of the National Education Longitudinal Study of 1988. Beginning in 1988, data were collected on a cohort of 25,000 eighth graders attending 1,000 public and private schools across the United States. The study was designed to provide data about various educational processes and outcomes experienced by youth as they progressed through their educational careers. In the spring of 1990, a follow-up survey of the initial cohort was conducted. Data from this first follow-up survey include a number of items relevant to interpersonal relations and delinquent behavior. The delinquency measure was regressed on the measures of peer relations, social control, and differential association; separate regressions were performed for males and females. Although it was hypothesized that problems with peers would affect female delinquency and would have a larger effect on female than male delinquency, the data provided little support for this prediction. The only peer variable to be significantly associated with female delinquency was positive relations with the opposite sex. Contrary to predictions, females who reported positive relations were more rather than less delinquent. This might be explained in terms of learning and opportunity theories; females who are popular with and spend a lot of time with boys are more exposed to male deviance and may find that they have more opportunities to engage in such delinquent behavior as drug and alcohol use. Suggestions are offered for future related research. 3 tables, 4 notes, and 76 references