Current prevalence rates of Conduct Disorder (CD) in girls may be an underestimate due to inappropriate diagnostic criteria, biased perceptions by those responsible for reporting problematic behavior, and differential social constraints for each gender. Relatively few published studies of CD and related behaviors in girls exist. Available evidence suggests adolescent girls with CD have a poor outcome including early and violent death, arrest, substance abuse and dependence, antisocial personality disorder, failure to finish high school, pregnancy, sexual promiscuity, and contraction of sexually transmitted disease. Even with its relatively low, possibly underestimated prevalence rate in comparison with that of boys, CD has been found to be the second most common psychiatric disorder in adolescent girls. In addition to examining possible reasons for the lack of research on CD in girls, this article reviews possible risk factors and suggested assessment and intervention strategies for this population. Particular attention is paid to implications for practitioners in the school setting.