Boys consistently report higher rates of serious offending during late adolescence than do girls, yet research is mixed regarding the ways in which males and females may differentially experience risk and protection in their families, schools, peer groups, and as individuals. This article examines gender differences in 22 psychosocial risk and protective factors associated with serious delinquency. Based on self-reported information from 7,829 10th-grade students completing the Communities That Care Youth Survey, all psychosocial factors were significantly related to serious delinquency for both sexes. For 12 of the 22 factors, the strength of the association was significantly greater for males, and, for 18 factors, boys reported higher levels of risk exposure and lower levels of protection than did girls. Together, these findings suggest that boys' greater involvement in serious delinquency is due to the combination of experiencing more risk and less protection than girls and the greater association of these predictors with serious delinquency for boys compared to girls. Implications for prevention programming are discussed.