The discovery of differential effects would lend support to strain theory, a theory that emphasizes the negative consequences of poor grades and low educational expectations for the adolescent's economic future. Strain theorists also assert that educational factors have a greater effect on the delinquent behavior of boys than girls and of older than younger adolescents. By contrast, control theorists argue that immediate problems are more salient than commitment to long-range goals and they would expect school factors to have separate or independent effects on delinquent behavior. Data for the study came from 385 interviews with junior and senior high school students in Wayne County, Michigan. The study tested for three-way interactions (grade level and sex by school factors by delinquency). The following specific hypotheses were tested: the effects of school factors on delinquency are greater for boys than for girls and for older adolescents than for younger adolescents. The findings provided mixed support for both theories. No significant association was found between school flunking and delinquency, although those students who thought their chances of graduating were bad were more likely to be delinquent. Involvement in school sports and clubs was also not significantly related to delinquency. The association between expected education and delinquent behavior was greater for older than younger adolescents. The associations between attitudes toward school and delinquency were found to be greater for girls than for boys. The findings reveal a need for further research on the delinquent behavior of adolescents. Tabular data, footnotes, and 30 references accompany the article.