The authors conducted a review of the literature with regard to child and adolescent mental health intervention, from which they identified 20 unique publications and 12 separate interventions. These interventions encompassed depression, anxiety, substance abuse, eating disorders, and mental health promotion. Studies were heterogeneous, with a wide range of study designs and comparison groups creating some challenges in interpretation. However, modest evidence was found that Internet interventions showed benefits compared with controls and preintervention symptom levels. Interventions had been developed for a range of settings, but tended to recruit middle-class participants of European ethnicity. Internet interventions showed a range of approaches toward engaging children and incorporating parents and peers into the learning process.