Data were obtained from the 1977-1979 Seattle Youth Study, which included self-reported measures of school experiences and delinquent behavior for 1,508 high school students. Gender-based school and delinquency hypotheses were evaluated from two empirical perspectives. First, within-class tests were conducted to explore potential differences and similarities in school determinants of delinquency for males and females. Second, between-class tests were employed to assess the extent to which being either male or female conditioned or interacted with the school-delinquency relationship. Increases in positive attitudes toward achievement and toward school produced significantly stronger reductions in delinquency for males than for females. More involvement in school activities caused stronger reductions in delinquency for females than for males. Increases in positive attitudes toward teachers produced significantly stronger reductions in delinquency for females than for males. Differences in community context changed the school-delinquency relationship more for females than for males. Findings support a power-control interpretation of school-based gender differences in delinquent behavior. 51 references and 5 tables