Multiple group analysis and general growth mixture modeling was used to determine whether aggressive?disruptive behavior trajectories during elementary school, and their association with young adulthood antisocial outcomes, vary by gender. Participants were assessed longitudinally beginning at age 6 as part of an evaluation of 2 school-based preventive programs. Two analogous trajectories were found for girls and boys: chronic high aggression?disruption (CHAD) and stable low aggression? disruption (LAD). A 3rd class of low moderate aggression?disruption (LMAD) for girls and increasing aggression? disruption (IAD) for boys also was found. Girls and boys in analogous CHAD classes did not differ in trajectory level and course, but girls in the CHAD and LAD classes had lower rates of antisocial outcomes than boys. Girls with the LMAD trajectory differed from boys with the IAD trajectory.