Untreated or undermined anxiety at elevated levels have a negative impact on youth's mental health, leading to various problems in the educational and psychosocial domain. School-based interventions play an important role in the prevention of anxiety disorders in children and adolescents. Accordingly, a group therapy program which includes cognitive behavioral therapy techniques was developed to reduce subclinical anxiety in school-aged children. This program is suitable for children aged 12 to 15 years and can be delivered in groups consisting of 6-8 children. The content of this program can be adapted for use in clinical settings but first it should be revised and tested for validity in clinical samples. The effectiveness of this program in the school environment was supported by an experimental study. Finally, it is necessary to have the basic knowledge about cognitive behavioral therapy techniques as well as training in childhood psychopathology in order to apply the prevention program presented in this book.